XTAP(eXpandable Transient Analysis Program)
Version 2.4
Instruction ManualCentral Research Institute of Electric Power Industry (CRIEPI)
December 2022

XTAP (eXpandable Transient Analysis Program) Version 2.40
Development
Central Research Institute of Electric Power Industry (CRIEPI)Energy Innovation Center, Electric Power Engineering Research Laboratory, System
Engineering Research Laboratory
http://criepi.denken.or.jp/en/index.html
Development assistance
Denryoku Computing Center
http://www.dcc.co.jp/
Support information
Access the URL below after obtaining an ID and password from CRIEPI.
http://www.xtap.jp/
Copyright information
XTAP Ver.2.40 was partly developed using the following redistributable programs:
AnaGram - A System for Syntax Directed Programming
Version 3.0 Copyright © 1993-1999 Parsifal Software
Out of The following components of MATLAB 8.6.0.267246 (R2015b), 1984-2015, The
MathWorks, Inc.), MATLAB Compiler and its runtime libraries, MCR Libraries(Licensing to users is restricted under the license agreement between CRIEPI and The
MathWorks, Inc.)
ComponentOne Studio
Copyright (c) 2004 GrapeCity, Inc.
SPREAD for Windows Forms
Copyright (c) 2004-2012 GrapeCity inc.
Developer credits
CRIEPI
Taku Noda, Rikido Yonezawa, Yohei Tanaka, Tomo Tadokoro, Guilherme Cirilo Leandro, Toru
Miki, Kazuyuki Ishimoto, Toshiya Ohtaka, Naoki Gibo, Toshiaki Kikuma, Shinsuke Aida,
Shogo Fukui, Jota Suzuki, Koya Naruse, Shugo Takahashi, Orie Sakamoto (currently at
Sophia University), Kenichiro Sano (currently at Tokyo Institute of Technology)
Denryoku Computing Center
Kiyoshi Takenaka, Itaru Watanabe, Yoichi Sekiba, Takayuki Nakajima, Hiroshi Takizawa,
Toshiyuki Okada, Masahiko Takemura, Shigetaka Suzuki, Tsutomu Maejima, Mitsuo
Takateyama, Minoru Ishiwata, Yasushi Yokoi, Ryo Anan, Taro Yoshida, Wakako Ishiwata,Izumi Ichimori, Mamoru Hosoya, Tadahiko Nagaoka
Trademark
XTAP is a registered trademark of the Central Research Institute of Electric Power Industry(CRIEPI).

Contents
1

Introduction.................................................................................................................. 1
1.1 ....... XTAP ...................................................................................................................... 1
1.2 ....... Features of XTAP ................................................................................................... 1
1.3 ....... Operating environment ........................................................................................... 1
1.4 ....... Software upgrade caution....................................................................................... 2
1.5 ....... XTAP-related CRIEPI reports ................................................................................. 3

2

Starting XTAP, Main Window ...................................................................................... 5
2.1 ....... Starting XTAP ......................................................................................................... 5
2.2 ....... Terminology ............................................................................................................ 7
2.3 ....... Main window ........................................................................................................... 8
2.4 ....... Menus in the main window ..................................................................................... 93

Workflow From Circuit-Diagram Creation Through Analysis ................................ 22

4Creating Circuit Diagrams ........................................................................................ 24
4.1 ....... Part types ............................................................................................................. 24
4.2 ....... Part placement (electrical-circuit part/control-block part) ...................................... 24
4.3 ....... Part operations ..................................................................................................... 26
4.4 ....... Part properties screen .......................................................................................... 31

5Part Connections ....................................................................................................... 35
5.1 ....... Creating electrical-circuit wires ............................................................................. 35
5.2 ....... Electrical-circuit wire (node) properties................................................................. 38
5.3 ....... Creating control-system wires .............................................................................. 39
5.4 ....... Control system wire properties ............................................................................. 40
5.5 ....... Creating multiple-signal control system wirings .................................................... 40
5.6 ....... Creating three-phase buses ................................................................................. 43
5.7 ....... Creating line concentrators ................................................................................... 47

6

Analysis Processes ................................................................................................... 52
6.1 ....... Analysis settings ................................................................................................... 53
6.2 ....... Analysis procedure (analysis type: transient analysis) ......................................... 54
6.3 ....... Analysis procedure (analysis type: steady-state initialization → transient analysis)........... 58
6.4 ....... Analysis procedure (analysis type: power flow calculation → steady-state
initialization → transient analysis) ................................................................................... 62
6.5 ....... Analysis procedure (analysis type: frequency characteristic calculation) ............. 68
6.6 ....... Files related to analysis processes ....................................................................... 71
6.7 ....... Search function .................................................................................................... 72

7

Consecutive-Analysis Function ............................................................................... 73
7.1 ....... Overview of consecutive analysis function ........................................................... 73
7.2 ....... Opening the consecutive-analysis settings window .............................................. 73
7.3 ....... Consecutive-analysis settings window ................................................................. 74
7.4 ....... Setting the number of cases and of parameters ................................................... 75
7.5 ....... Parameter input method ....................................................................................... 76
7.6 ....... Ending/canceling parameter settings.................................................................... 80
7.7 ....... Executing a consecutive analysis ......................................................................... 81
7.8 ....... Statistical processes for analysis results .............................................................. 83
7.9 ....... Executing statistical processes ............................................................................. 84
7.10 ..... Displaying analysis results in XPLT ...................................................................... 88

8

Statistical Switching-Surge Calculation Function .................................................. 89
8.1 ....... Overview of statistical switching-surge calculation function.................................. 89
8.2 ....... Opening the settings window for a switching-surge calculation ............................ 89-i-8.3 ....... Analysis example.................................................................................................. 90
9

XPLT (Graphing Program)......................................................................................... 93
9.1 ....... Starting XPLT ....................................................................................................... 93
9.2 ....... Selecting the analysis result files .......................................................................... 93
9.3 ....... Displaying graphs ................................................................................................. 94
9.4 ....... Graph editing ...................................................................................................... 103
9.5 ....... Menus................................................................................................................. 106

10 Creating and Editing Macro Parts .......................................................................... 114
10.1 ..... Packaging procedure (creating macro parts) ...................................................... 114
10.2 ..... Changing macro parts ........................................................................................ 120
10.3 ..... Editing macro-part icons ..................................................................................... 123
10.4 ..... Connection-terminal settings .............................................................................. 130
10.5 ..... Registering parameters/formulas ....................................................................... 133
10.6 ..... Part-category window composition; creating/deleting categories ....................... 137
11 Other ......................................................................................................................... 139
11.1 ..... Starting XTLC (line constants calculation program) ........................................... 139
11.2 ..... Starting XFIT (system identification program) .................................................... 139
Appendix 1. XTLC (Line Constants Calculation Program) Instruction Manual ......... 141
Appendix 2. XFIT (System Identification Program) Instruction Manual ..................... 177- ii -

1 Introduction

1.1

XTAP

XTAP (Expandable Transient Analysis Program) is a program for analyzing transientphenomena in power systems and other electric circuits at the waveform level. This
type of analysis has so far been done using programs developed outside Japan, suchas EMTP. XTAP is thus the first program in this field developed specifically in Japan. It
provides superior analysis performance compared to conventional programs foranalyzing power-electronics devices, such as inverters for solar-power generation.
CRIEPI is also working on developing programs to meet the needs of the domestic
market.

1.2

Features of XTAP

Feature 1: High calculation precision, value stability
XTAP uses highly efficient calculation algorithms for value integration and circuit
formularization, to achieve a higher calculation precision and value stability thanconventional programs (see the list of CRIEPI reports in Section 1.5 for information oninternal program calculation principles and the algorithms used).
Feature 2: Reliable convergence performance (ideal for power-electronics circuit
analysis)Thanks to its proprietary convergent calculation and equation solution algorithms,
XTAP quickly performs circuit analysis calculations, even in cases of extreme
nonlinearity. The analysis is almost perpetual (i.e., it does not converge). This algorithm
is ideal for power-electronics circuits.
Feature 3: Provision of device models for domestic power systems
Models needed for domestic power-system analysis are provided standard. Various
control blocks for creating device-control mechanisms can be used. Help information
is provided in Japanese for all models.
Feature 4: Graphical user interface
The XTAP interface simplifies circuit creation, enabling the creation of power-systemmodels and power-electronics circuits. Analysis results (voltage/current values at userspecified locations) can also be checked using simple operations.

1.3

Operating environment

XTAP requires the following environment:
Operating system
Microsoft Windows 8, 8.1 (32-bit and 64-bit versions)OperatingsystemMicrosoft Windows 10 (32-bit and 64-bit versions)

Memory32-bit OS: 2.0 GB or more (4.0 GB or more recommended)
64-bit OS: 4.0 GB or more (8.0 GB or more recommended)PC

Hard-disk
8 GB or morecapacity
Software required
MATLAB Compiler Runtime R2015b
SoftwareMicrosoft .NET Framework 4.8.1 or newer-1-

Screen DPI setting
Text may not be displayed properly by XTAP if the DPI setting of the screen is changed.
XTAP will display text correctly for a standard setting of 96 DPI. An increasing in thisstandard setting by the user (e.g., 125% or 150%) is not problematic. The standard
default setting in Windows is often 96 DPI, but the DPI setting can be changed in the‘display properties’ dialog. Consult the help information provided with your operating
system for instructions.

1.4

Software upgrade caution

XTAP Version 1.20 and later versions are backward-compatible, supporting circuitdrawing files (*.xsf files) created by older versions. When the below dialog box appears,
click ‘Continue’ to start conversion of the file so that it can be used in the current version.
The file conversion process is done either automatically or manually by the user (forexample, in the case of user-defined components). Note that once a circuit-drawing filehas been converted to a more recent version of XTAP, it can no longer be opened using
the older version.

For details regarding this file conversion, see “Using a circuit diagram file (xsf file)created in an older version” on the XTAP user support site.

-2-

1.5

XTAP-related CRIEPI reports

Reports released by CRIEPI relating to the development of XTAP are listed below.
The full text of these reports is available free of charge from the CRIEPI download site.
(The reports are in Japanese with English abstracts.)
Report No.

Title

H06002Development of an Electromagnetic Transient Analysis Program for Power Systems (Part 1) -Fundamental Design --R06017Development of Inverter Simulation Program (Part 1) - Modeling of MOSFET and Diode -H07005

A Transmission Line Model for Electromagnetic Transient Analysis Based on the Frequency
Region Partitioning Algorithm

H07004Development of an Electromagnetic Transient Analysis Program for Power Systems (Part 2) Development of a Fundamental Algorithm for Steady-State Calculation -R07016Development of Inverter Simulation Program (Part 2) - Verification of Analysis Accuracy Based on
Actual Measurement -R08022Development of instantaneous simulation method of an induction motor for transient analysis

R08027

Design Guideline and Marginal Performance of a SiC Diode Applied Inverter

R08015

Accelerated Electromagnetic Transient Simulations of Power Electronics Circuits using a Variable
Time Step Algorithm

H08002Development of an Electromagnetic Transient Analysis Program for Power Systems (Part 3) Improvements of Convergence Properties for Nonlinear Circuits -H09007Development of an Electromagnetic Transient Analysis Program for Power Systems (Part 4):
Practical Steady-State Initialization

R09007Development of Support System of Setting and Coordination between Protection Relays- Methodof Checking Coordination including Earth Fault Protections in Distribution Systems with Isolated
Neutral System-

R09010Optimum Circuit Configuration of SiC Device Applied STATCOM for Distribution System

R09015

Stable Operation Technique for PCS of PV Power Generation at Grid Recovery after Voltage Sag

R10008Study on introduction of SN transition type FCL into looped distribution system

R10025Development of a synchronous machine model considering the magnetic saturation in the stator
core for electromagnetic transient analysis of power systems

H10008Study on Lightning Protection Design for Distribution, Telecommunication and Consumer Circuits(1) -Analytical Study on Lightning Overvoltages on Distribution Lines with Telecommunication
Cables-H11010

Proposal of a Sparkover Model for Short Wave Tail Impulse Voltage Waveforms Applied toDistribution Insulators

H11013Characteristics of Spark Discharge on Faulty Insulation of 6.6kV Distribution Lines -A Proposal of
Evaluation Method for Low Frequency Pulsed Electromagnetic Interference-

H11009Development of an Electromagnetic Transient Analysis Program for Power Systems (Part 5): A
Fast Algorithm for LU Decomposition of a Large Sparse Matrix

H11006

Evaluation of Line Constants of Short-Length Underground Cables: Development of a
Measurement Method and Validation of a Calculation Method

H12005

Review of Simulation Methods for Electromagnetic Transients in Power Systems and Simulation
Cases Using XTAP (Part 1): Switching Transient Overvoltage Simulations

R12005Development of an Electromagnetic Transient Analysis Program for Power Systems (Part 6) Performance Improvements for Nonlinear Circuits -R12020Preventing Islanding by Distributed Power Generation at Transmission System Fault- Evaluationof Characteristic of Detecting Islanding by Power Conditioning Subsystem for Interconnecting
Many Distributed Power Generations in Area with Rotated Type Distributed Power Generation -R12010Harmonic Instability at Parallel Operation of Line Commutated Converter and Voltage Sourced
Converter

H13007

A Dynamic Voltage Simulation Method for Power Distribution Systems by Using Electromagnetic
Transient Analysis (Part 1): Modeling of Distribution Substation and SVR-3-

H13005

Development of an Electromagnetic Transient Analysis Program for Power Systems(Part 7): Fast
Simulations by Parallelization of Updating Process of Circuit Components

H13010Development of an Electromagnetic Transient Analysis Program for Power Systems (Part 8): Fast
Simulations by Single-Phase Phasor-Based Modeling of Remote Power Systems

R13027Development of Modular Multilevel Converters Model for High Speed Electromagnetic Transient
Analysis

H14013Development of a Frequency-Dependent Line Model for Electromagnetic Transient Simulations
without Model Identification Problems (Part 1): Simulation Performance of an FDTD-Based LineModel

H14014

A Dynamic Voltage Simulation Method for Power Distribution Systems by Using Electromagnetic
Transient Analysis (Part 2): Modeling of STATCOM

R14016

Control and Protection Scheme of HVDC System with Modular Multilevel Converter using Full
Bridge Cell - Part2: Development of an Operation Method under AC High-Voltage Situation and a
Method for Fast Start-

H15004Development of an Electromagnetic Transient Analysis Program for Power Systems (Part 9): A
Fast Frequency-Scan Algorithm

H15014

A Fast Simulation Algorithm for Distribution-System Transients Based on the Theory of Dynamic
Phasors (Part 1): Proposal of Fundamental Concept

R15022Development of Converter Model for High-speed Transient Analysis - Averaged Model with
Rectifier Circuit --4-

2 Starting XTAP, Main Window

2.1

Starting XTAPThe following screen appears after XTAP is launched:

When the program starts, a menu appears showing the options ‘New’ and ‘Open
existing file’. To create a new circuit diagram, select ‘New’. To open an existing circuit
diagram (*.xsf file), select ‘Open existing file’.
It is also possible to double-click an xsf file displayed in Explorer in order to launch
XTAP and open that circuit diagram (if an xsf file is double-clicked while XTAP is alreadyrunning, that file will be opened in the running XTAP). Another method of opening an
xsf file is to drag and drop it onto the XTAP window.

Selecting ‘New’ opens a blank canvas like the one shown below.

-5-Selecting a circuit diagram (*.xsf file) using ‘Open existing file’ or ‘Recently used file’opens the selected circuit diagram.

-6-

2.2

Terminology

Terms used within XTAP are defined as follows.
part
Resistors (linear), sine-wave voltage sources and other component elements ofelectrical circuits or control blocks are referred to as ‘parts’. The term refers to the itemsin the ‘part category’ window on the left side of the screen.
node
A wire used to connect parts in an electrical circuit is called a ‘node’. Control-systemwires connecting control blocks are used to denote a connection between the blocks,
and are different from nodes.
branchA ‘branch’ is a synonym of ‘part’.
packaging, macroing
A set of several parts that compose an electrical circuit or control block can beregistered collectively as a single part. This operation is known as ‘packaging’. The
operation of packaging electrical circuits or control blocks containing parts created bypackaging is called ‘macroing’. Parts created in this manner are sometimes referred toas ‘macro parts’.

-7-

2.3

Main window

This section describes the main window, which appears when ‘Create circuit diagram’has been selected from the ‘File’ menu and a new circuit diagram is opened.

1
3
2

4

5

6

7

8

9

1. Menus in the main window
See Section 2.4 for details.
2. ‘Part category’ window
This window is used to register parts such as electrical-circuit parts and control-system
block parts. ‘99 User's Components’ is used to register a user-packaged part. Parts
other than ‘99 User's Components’ cannot be changed.
3. Zoom settingThis setting is used to change the screen-display size by selecting the desired
magnification. The screen display size can also be changed by holding down the ‘Ctrl’
key on the keyboard while turning the mouse wheel. At this time, it operates so that themouse position at the moment when Ctrl key is pressed can be located at the center of the screen.
4. XPLT button
This button starts XPLT (the graphing program). XPLT is described in Chapter 9.
5. XTLC button
This button starts XTLC (the line-constants calculation program). XTLC is described inAppendix 1.
6. XFIT button
This button opens XFIT (the system-identification program for XTAP). XFIT is describedin Appendix 2.
7. Circuit-diagram canvas
This space is used to place the parts and create the circuit diagram.

-8-8. Gray circuit diagram canvas background color
The canvas background color is gray when editing a circuit diagram, or when editing acircuit in a packaged part (editing a macro part). Part editing is described in Chapter
10.
9. Circuit diagram canvas coordinate display
When the cursor is located over the canvas, its coordinates in the canvas coordinate
system are displayed at the bottom-right corner of the window.

2.4

Menus in the main window

This section describes the top-level XTAP menus and the corresponding menu items.

(1) File (F) menu

Create circuit diagram• opens a new (blank) circuit diagram. The same operation can be performed byclicking the toolbar button indicated below.
Open circuit diagram• opens a previously created circuit diagram (*.xsf file). The same operation can be
performed by clicking the toolbar button indicated below.
Create component• allows the definition of a new part. Defined parts are registered in the ‘99 User's
Components’ category.
Open component• opens a part already registered as a user-defined part.

-9-

Rename component• allows a change in the name of a part that was previously registered as a user-defined
part.
Create category• creates a new category in the ‘99 User's Components’ category.
Save• saves the circuit diagram, replacing any previous version with the current version.
The same operation can be performed by clicking the toolbar button indicated below.
This button is active only when the circuit diagram has been changed after being
opened. The button is inactive (with a gray appearance) otherwise.
Save as• saves the circuit diagram under a new name.
Export• outputs and saves the part information registered in the ‘Part category’ window inthe ‘XTAP Components Backup File’ format. It is also possible to output the image ofa circuit canvas as an image file. Selecting this menu item displays the window
shown below. This window can be used to enter a file name and select the desired
image-file type in which to save the circuit canvas. The EMF, bitmap, GIF, JPEG,
PNG, or TIFF file format can be selected.

Import• reads the part information output by the export function into XTAP, and registers it inthe ‘part category’ window. It is possible to either import all part information as a batch(automatic part importing) or select parts one at a time (individual part importing).
Page settings• defines settings for printing, such as the page size and printer settings.

- 10 -

Print• prints the circuit diagram. This operation can also be performed by clicking the toolbar
button indicated below.
Print preview• displays a preview of how the printed circuit diagram will appear. This operation canalso be performed by clicking the toolbar button indicated below.
Exit application• terminates the XTAP application.

- 11 -

(2) Edit (E) menu

Undo
• Undo one of the changes made to the circuit.
Redo• Restores one of the changes made to the circuit canceled by “Undo”.
Cut• Cuts the selected component or node from the circuit diagram.
Copy• Copies the selected component or node.
Paste• Pastes the “cut” or “copied” component or node into the circuit diagram. The names of thepasted component and node are as follows.
¾ Component: Will be renamed to a unique new name.
¾ Node9 Default name: Will be renamed to a unique new name.
9 User-set name: Will be pasted with the original name (considered the same node).
When pasting, a message indicating this will appear.

- 12 -

Keep Name and Paste• Paste the “cut” or “copied” components or node to the circuit diagram while keeping the name.
It operates as follows, depending on components and nodes that exist in the circuit of the paste
destination.
¾ If a component with the same name exists:
XTAP does not allow a component with the same name to be placed on the samehierarchy. Therefore, the following message will appear, asking you to select either
renaming and pasting or canceling the paste operation. If you select “Yes to all”, XTAP
will automatically select “Yes” for all subsequent cases where the same message
appears.

¾ If a node with the same name exists:
In XTAP, nodes with the same name existing on the same hierarchy are considered tobe the same node (even if they are far apart on the circuit diagram campus). Therefore,
the following message will appear, asking you to select either pasting while keeping
the name or canceling the paste operation. If you select “Yes to all”, XTAP willautomatically select “Yes” for all subsequent cases where the same message appears.

Delete• Delete the selected component or node.
Select All• Copies the selected component or node.

- 13 -

(3) Circuit (C) menu

Select• selects a component (e.g., a part or wire) located on the circuit diagram canvas. This
operation can also be performed by clicking the toolbar button indicated below.
Electrical-circuit wire
• switches to the mode used to create an electrical circuit wire. This operation can also
be performed by clicking the toolbar button indicated below.
Three-phase bus• switches to the mode used to create a three-phase bus. This operation can also be
performed by clicking the toolbar button indicated below. See Section 5.6 for details of
how to create a three-phase bus.
Electrical-circuit N-line concentrator• switches to the mode used to create a line concentrator that packages multiple
electrical circuit wires. This operation can also be performed by clicking the toolbar
button indicated below. See Section 5.7 for details of how to create a line concentrator.
Control-system wire
• switches to the mode used to create a control-system wire. This operation can also
be performed by clicking the toolbar button indicated below. See Section 5.3 for detailsof how to create control-system wires.
Multiple-signal control system wiring• switches to the mode used to create wiring for a multiple-signal control system. Thismode can also be selected from the ‘Multiple-signal control system wiring’ icon button.
See Section 5.5 for details.
Control-system N-line concentrator• switches to the mode used to create a line concentrator that packages multiple control
system wires. This operation can also be performed by clicking the toolbar button
indicated below. See Section 5.7 for details of how to create a line concentrator.

- 14 -Text string• enters a comment in the circuit diagram. This operation can also be performed byclicking the toolbar button indicated below.
Search• searches for a component placed in the circuit diagram. This operation can also be
performed by clicking the toolbar button indicated below. See Section 6.7 for a
description of the search function.
Package• packages the parts selected in the circuit diagram and creates a new composite part(a macro part). This operation can also be performed by clicking the toolbar button
indicated below. This menu option is only active if a part is selected (otherwise the icon
is grayed out). See Section 10.1 for details of how to package parts (create macroparts).
Edit all branch properties• allows editing of the recording properties and display properties of all the branches(circuit parts and control parts) in the currently active layer simultaneously. This
operation can also be performed by clicking the toolbar button indicated below.
Selecting this menu item displays the following window. Use this window to turn therecording/display properties of parts ON or OFF. Clicking on one of the cells in thecolumn headings at the top left of the table sorts the list in the corresponding order.
Each click of these cells toggles the sort order between ascending and descending.
Changes made in this window are applied to the corresponding parts. To switch
between circuit parts and control parts, use the tabs at the top left of the window.

Edit all node properties• lets you edit the recording properties and display properties of all the nodes(electrical-circuit and control-circuit wires) in the currently active layer simultaneously.
This operation can also be performed by clicking the toolbar button indicated below.
The operation performed by selecting this menu item is the same as for the ‘Edit all
branch properties’ menu item.

- 15 -

Display all branch names• displays the names of all the branches in the currently active layer. This operation
can also be performed by clicking the toolbar button circled below.
Selecting this menu item, or clicking the corresponding toolbar button, displays all the
branch names. A further selection of the menu item or click of the button disables thisfunction, restoring the branch-name display settings specified in the properties for eachpart. Note that this function has no effect on branches that are already set to display
the branch name. Also, note that selecting this menu item has no effect on the partproperties, unlike when the display properties are turned ON or OFF by selecting the‘Edit all branch properties’ menu item.

Display disabled

Display enabled

Display all node names• displays the names of all the nodes in the currently active layer. This operation canalso be performed by clicking the toolbar button indicated below.
Selecting this menu item, or clicking the corresponding toolbar button, displays all thenode names. A further selection of the menu item or click of the button disables thisfunction, restoring the node name display settings specified in the properties for eachnode. Note that this function has no effect on nodes that are already set to display thenode name. Also note that selecting this menu item has no effect on the node properties,
unlike when the display properties are turned ON or OFF by selecting the ‘Edit all node
properties’ menu item.

- 16 -

(4) Analysis (A) menu

Analysis settings• opens the settings screen used to set the analysis conditions. This operation can also
be performed by clicking the toolbar button indicated below. Analysis processes aredescribed in Chapter 6.
Run analysis• performs an analysis using the previously set analysis conditions. This operation canalso be performed by clicking the toolbar button indicated below. An analysis cannot
be executed when the circuit has been changed. In this case, the menu item and button
for this operation are inactive (grayed-out and inoperable). You must first save thecircuit before performing an analysis on it.
Save and run alysis• saves changes to the current circuit and then runs the analysis.You can also selectfrom the "Save and run analysis" icon button.This function can also be operated bypressing the F5 key.
Consecutive-analysis settings• opens the ‘analysis settings’ screen, used to set multiple combinations of circuit
parameters such as circuit resistances, inductances, and breaker ON times (multiple
analysis cases), and to execute those multiple analysis cases consecutively andautomatically. This menu item is also used to define the settings for statistical switchingsurge calculations. The operation of this menu item can also be executed by clicking
the toolbar button indicated below. See Chapter 7 for details.
Run consecutive analysis• performs a consecutive analysis using the previously set consecutive-analysis
conditions. This operation can also be performed by clicking the toolbar button
indicated below. Note that a consecutive analysis cannot be executed when theconsecutive-analysis settings have not been entered or the circuit has been changed.
In these cases, the menu item and button for this operation are inactive (grayed-out
and inoperable). The circuit must be saved before performing a consecutive analysis.

- 17 -

(5) View (V) menu

Toolbar• enables/disables the display of the toolbar in the XTAP main window.
Status bar• enables/disables the display of the status bar in the XTAP main window.
Grid display• enables/disables the grid display in the circuit-diagram canvas. This operation canalso be performed by clicking the toolbar button indicated below.
Print-area display• enables/disables the print-area display on the circuit-diagram canvas. Enabling theprint-area display shows the set print-sheet positions (the print area for each sheet) inthe circuit canvas when two or more horizontal or vertical sheets have been set in thecanvas-size settings. The operation of this menu item can also be performed by clicking
the toolbar button indicated below.
The screen shot below shows an example of the display produced when the print-areadisplay has been enabled, and the ‘3 horizontal/2 vertical’ settings have been selectedin the canvas-size settings (with A4 size paper). The dotted green lines indicate theprint area of each sheet. Printing with these settings will result in six A4 sheets being
printed.

- 18 -

(6) Tools (T) menu

Circuit-diagram canvas size
• allows a change to the size of the circuit-diagram canvas. This size is specified interms of the paper size supported by the selected printer driver, and the number ofsheets in the horizontal and vertical directions (with a maximum of nine sheets in thehorizontal direction and six sheets in the vertical direction).

Component canvas size
• changes the size of a part icon’s canvas. It is possible to specify any width and height
for the size of the component canvas. See Section 10.3 for details.
XPLT (graphing program)• starts XPLT (the graphing program). XPLT is described in Chapter 9.
XTLC (line-constants calculation program)• starts XTLC (the line-constants calculation program). XTLC is described inAppendix 1.
XFIT (system-identification program)• starts XFIT (the system-identification program for XTAP). XFIT is described inAppendix 2.

- 19 -

(7) Window (W) menu

Opens a new window• Opens the same xsf file that is currently open in a new window.
Cascade• Switches the display method for the circuit diagram files to a multi-window view to cascade
all circuit diagrams that are currently open.
Vertical• Switches the display method for the circuit diagram files to a multi-window view to display
all circuit diagrams that are currently open vertically at equal intervals.
Horizontal• Switches the display method for the circuit diagram files to a multi-window view to display
all circuit diagrams that are currently open horizontally at equal intervals.
Close All
• Closes all circuit diagrams that are currently open.
Arrange Icons• Arranges the small windows at the bottom of the screen when the window display is
minimized.
“Name of the open circuit diagram file” *May be none or multiple.
The window name of the currently-open circuit diagram file will be displayed on the list.
When editing a hierarchized component, it will be recognized as a single window. If one of
the windows is selected here, the selected window will be displayed in the foreground.

- 20 -

(8) Help (H) menu

User's Manual• Opens the same xsf file that is currently open in a new window.
Cascade• Opens a PDF file of the XTAP user’s manual (this document). (The file will be opened by theapplication associated with the PDF file.)
Version Information• Displays the version information of the currently activated XTAP.

- 21 -

3 Workflow From Circuit-Diagram Creation Through Analysis

The XTAP workflow needed to create a circuit, execute its analysis, and graph theresults is illustrated below. See the sections indicated in the flowchart for descriptionsof the corresponding procedures.
⚪ Using XTAP (circuit creation/calculation program)Creating circuit
Part placement(circuit parts, control block parts)

See Section 4.2

Part property settings(parameter input/output specifications, etc.)

See Section 4.4

Part macroing(creation of macro parts)
Part connection(circuit creation)

See Chapter 10
See Chapter 5

Selecting analysis typeTransientanalysisSee Section 6.2

Steady-state initialization→ Transient analysis

See Section 6.3

Flow calculation → Steady-state initialization→ Transient analysis
Frequency characteristic
calculation

See Section 6.4

See Section 6.5

Analysis execution
Analysis condition settings(analysis time, output file, etc.)

Analysis execution

Analysis result file (*.xpf)
creation- 22 -

Analysis
result file(*.xpf)⚪ Using XPLT (graphing program)
Graphing

See Chapter 9
Analysis
result file(*.xpf)Load analysis result file (*.xpf)

Normal graphing● Time-series graphs● XY plot● Frequency characteristic
graphsModified graphs● Integrals● Fourier transforms● Fourier series
expansions● Constants (a*f(t)+b)- 23 -

4

Creating Circuit Diagrams

4.1

Part types

The parts in XTAP are of the following types:
1. Electrical-circuit parts
These parts constitute electrical circuits and include resistors, power supplies, andswitches. Electrical circuit parts can be connected to each other either directly (byred square terminals), or to control parts using components such as voltage/current
probes (control outputs), and controller control voltage/current sources. There areboth single-phase and three-phase parts, both of which have different terminals. A
voltage, current, or instantaneous power can be viewed as forming the part output.
2. Control-block parts
These parts constitute control blocks. In control blocks, signal inputs are denoted as
yellow terminals, and outputs as blue terminals. A blue terminal output is connected
to a yellow terminal. There are both single-signal and multiple-signal wirings, both ofwhich have different terminals. Connections to electrical circuit parts are made using
components such as voltage/current probes (control outputs) and controller control
voltage/current sources. Output signals can be viewed as forming the part output.
3. Macro parts
These composite parts are created by packaging circuit parts or control-block parts
together. The rules for making connections to macro parts are the same as for theindividual parts. A macro part can be created within another macro part. Macro parts
can be referenced and edited in circuit diagrams.

4.2

Part placement (electrical-circuit part/control-block
part)

XTAP allows parts to be placed easily in a circuit diagram by ‘drag and drop’ using themouse.
1. From the ‘File’ menu, select ‘New (N)’ → ‘Create circuit diagram (X)’. In the ‘part
category’ window on the left, select the category containing the part you want to placein the circuit diagram. In the example below, a (linear) resistor is being added, andtherefore ‘01 RLCs’ is selected.

- 24 -

2. The parts registered in the ‘01 RLCs’ category are displayed. Selecting one ofthese parts displays its icon in the upper window.

3. Select the name of the part to place, and drag the selection onto the circuit
diagram. (‘00 Resistor (linear)’ has been selected in this example.)Drag

4. A (linear) resistor is placed on the circuit diagram.

- 25 -

4.3

Part operations(1) Selecting and moving parts
Clicking on a part selects it and displays green markers on it. The part can then be
moved freely by standard drag-and-drop.

Clicking on different areas of a part selects different items.

1
2
3
4
5
6
Clicking on
1 selects the caption label (part name). A double click allows the part to berenamed directly. It is also possible to rotate the orientation by 90 degrees from
‘Figure’ menu that appears by right-clicking the caption label (new function
added in Ver. 2.10). Text strings used as part names may contain upper- or
lowercase letters, numbers, and the underscore (_) character, but the firstcharacter cannot be a number. Japanese characters or other Asian-widthcharacters may not be used in part names.
Supported text string:‘a’ to ‘z’, ‘A’ to ‘Z’, ‘_’ or ‘0’ to ‘9’‘a’ to ‘z’, ‘A’ to ‘Z’, or ‘_’

2
3
4
5
6

selects the part itself. A double click opens the ‘properties’ screen. See Section
4.4 for information on the ‘part properties’ screen. Right-clicking displays the‘part’ menu, described in Item (2) on the next page.
selects the terminals (displayed in red), serving as the connection points to otherparts.
selects the ‘parameter’ label. Its value can be changed on the ‘properties’ screen.
Some parts do not have parameter labels.
selects the ‘initial value’ label, which can be changed on the ‘properties’ screen.
Some parts do not have an initial value label.
This line is displayed when the XPLT output has been specified. See Section
4.4 for more information.

- 26 -

(2) Part menu
The ‘part’ menu is displayed when right-clicking on a part.

Cut• cuts the part.
Copy• copies the part.
Paste• pastes the most recently cut or copied part. (See the note on the next page.)
Paste with same name
• pastes the most recently cut or copied part together with its name. (See the note on
the next page.)
Delete• deletes the part.
Disconnect• It is possible to cut a circuit line by right clicking the corresponding node and selecting"Disconnect".
Component - Show - Show Names• Show the component name in the diagram.
It is possible to do the same action by selecting the component and pressing the key"E".
Component – Show – Hide names• Hide the component name in the diagram.
It is possible to do the same action by selecting the component and pressing the key"D".
Component – Bring to front• moves the part to the foreground plane.
Component – Send to back• moves the part to the furthest background plane.
Component – Rotate Right 90°• rotates the part 90 degrees clockwise. This operation can also be performed by- 27 -

pressing the ‘R’ key on the keyboard when the part is selected.
Component – Rotate Left 90°• rotates the part 90 degrees counterclockwise.
Component – Flip vertically• flips the part vertically.
Component – Flip horizontally• flips the part horizontally. This operation can also be performed by pressing the ‘R’
key on the keyboard when the part is selected.
Properties• displays the ‘part properties’ screen.
● Difference between ‘Paste’ and ‘Paste with same name’ in part menu
Every part name in XTAP must be unique (no two part names can be the same).
Therefore, when a part is copied and pasted, the name of the pasted part is the default
part name appended with a number. However, when ‘Paste with same name’ isselected, the pasted part keeps the name of the original part provided that no part withthat name already exists on the target canvas.
Copied part

Paste

Paste with same name- 28 -

If a part with the same name already exists on the destination canvas, the message
shown below on the left appears, asking for confirmation to execute the paste operation.
(If the operation is executed, the part name becomes appended with an underscorecharacter.) Unlike parts, nodes with the same name may coexist on the same canvas.
However, in this case, program calculations will handle those nodes as if they were thesame node, even if they are at different locations on the circuit diagram (see Section
5.1). When executing the ‘Paste with same name’ command and if a node of the same
name already exists on the canvas, the message below on the right then appears.

- 29 -

(3) Macro part menu
In addition to the part menu items previously described, the following additional partmenu items can also be selected for macro parts. See Chapter 10 for details of how tocreate and edit macro parts. Macro parts are created by selecting portions of the circuit
diagram and packaging them as a new composite part.

Edit icon• displays a screen for editing the part’s icon. See Section 10.3 for details of how toedit icons.
Component properties• allows the specification of part information.
Edit packaged diagram• displays the part’s circuit diagram. See Section 10.2 for details of how to change
macro parts, and Section 10.4 for how to set connection terminals.

(4) Component manipulation by using the keyboard/mouse
Besides moving components placed in the diagram by dragging with the mouse, it
is possible to move components by selecting it and pressing the keyboard direction
keys.
Moreover, by pressing specific keys and selecting components, it is possible toselecting several components at once, to copy them or to move themhorizontally/vertically.
(Ctrl key) + (Left click)• It is possible to select several components at once. It shows the same behavior of(Shift key) + (Left click)(Shift key) + (Left click)• It is possible to select several components at once. It shows the same behavior of(Ctrl key) + (Left click).
(Ctrl key) + (drag and drop)• Copy the selected component. It can be used together with the shift key formoving the component horizontally/vertically.
(Shift key) + (drag and drop)• Move the selected component horizontally or vertically only. It can be used together
with the ctrl key for copying the component.
- 30 -

4.4

Part properties screen

A double click on a part displays the properties screen for that part.

(1) Parameters
Parameters are the properties that define the calculation conditions. Information abouta part’s parameters is provided in the help tab of its respective ‘properties’ screen.
Some control blocks have no specifiable parameters.

(2) Initial value
An initial value can be set for some parts. The way to set an initial value is describedin the help tab of the ‘properties’ screen.

- 31 -

(3) Recording• used to specify the items from which to generate outputs to graph. The checked items
will be displayed by XPLT (the graphing program). XPLT is described further in Chapter
9. Even when executing an analysis, only the checked items will be output as
waveforms. The appropriate checkboxes must therefore be checked to obtain the part
voltage, current, or power observations, as required. The following three types ofvalues can be output for circuit parts:
Branch voltage
Branch current
Branch power

In the case of control blocks, the output signal can be an output.

In macro parts, their internal parts, and the existence of various signals of nodes (nodevoltage, branch voltage, branch current, branch power, and control signal) can be
specified. When a macro part is turned off, even if any part’s signal recording is on
inside that macro part, output is still disabled.

- 32 -

(4) Display• enables or disables the display of various display labels for a part on the circuitdiagram canvas.

Name
The part name can be entered in the text box. Checking the checkbox displays thepart’s caption label on the circuit-diagram canvas. In some power transmission line
components, the line length can be displayed.
Parameter
Checking this checkbox displays the part’s parameter label on the circuit diagramcanvas. The parameter displayed is determined by the part type.

- 33 -

Recording
Checking this checkbox displays the items selected in the Recording tab as thepart’s output label on the circuit-diagram canvas. In the example below, the branchvoltage and branch current have been selected in the Recording tab.

Initial value
Checking this checkbox displays the part’s initial-value label on the circuit
diagram canvas. The initial value displayed is determined by the part type.

(5) Help• displays help information for a specific part.

(6) Acquiring information from power-flow calculations (macro parts
only)
User-created macro parts have a tab for power-flow calculation information. The
information in this tab is described in Chapter 8.

- 34 -

5

Part Connections

5.1

Creating electrical-circuit wires

This section describes how to create the electrical-circuit wires (nodes) that connect
different parts. As an example, a (linear) resistor and a (linear) inductor are first placedon the circuit diagram canvas as described in Section 4.2.

1.

Click the right terminal of the resistor. The mouse cursor becomes a plus sign(+), indicating the program has switched from part-selection mode to the mode
used for automatically creating electrical-circuit wires. To switch to this mode
manually, select ‘Electrical circuit wire’ from the ‘Circuit’ menu.

2.

Move the mouse to draw a line. In this example, the mouse is moved toward theleft terminal of the inductor. Lines cannot be drawn diagonally.

- 35 -

3.

Change the direction of the line by clicking at the desired point of change. In theexample below, the line has been drawn horizontally, vertically, and thenhorizontally again.

4.

Move the mouse to the left terminal of the inductor, then double-click to makethe connection. Once the terminals are connected, their red squares disappear.
If the terminal has a horizontal orientation, the line also needs to be connectedhorizontally. Horizontally oriented terminals cannot be connected from a verticaldirection.
Not connected

5.

When an electrical circuit wire (node) is created, the program automaticallyassigns it a unique name. Node names are not displayed under default display
settings. To check or change a node name, double-click the wire to open thenode’s ‘properties’ screen. See Section 5.2 for information on node properties.

- 36 -

6.

The node name can be changed in the node’s ‘properties’ screen (see Section
5.2). If the assigned node name already exists in the same layer, the nodes ofthat name will be considered to be the same node, and will be handled as if they
were connected, even if they are not connected in the canvas wiring.
Equivalent toconnection on rightSame node name

Whether or not a node name has been changed affects the node-name setting when
the node is copied/pasted.
⚪ When an unrenamed node is copied/pasted
The name of the pasted node is changed to a different unique node name, and thenode is handled as a different node.
⚪ When a renamed node is copied/pasted
The pasted node preserves the changed node name, resulting in the existence ofmultiple nodes with the same name. In this case, the following message appears.

As when changing a node name, care is needed since nodes with the same name aretreated as the same node.
Node namechangedNode name was changed,so same name ispreserved when pasted →Same node

Node name notchangedName is changed when
pasted → Different nodes- 37 -

5.2

Electrical-circuit wire (node) properties

Double-clicking a node displays its ‘properties’ screen.

(1) Display
This tab enables or disables the display of the electrical circuit wire name on the circuitdiagram canvas. Checking the checkbox displays the node name on the circuitdiagram canvas. The text box can be used to change the node name.

(2) Recording
Checking the checkbox in this tab sets XPLT (the graphing program) to display thenode voltage (voltage to ground). XPLT is described in Chapter 9.

- 38 -

5.3

Creating control-system wires

Unlike electrical-circuit parts, control system parts have input terminals (coloredorange) and output terminals (blue). Input terminals must always be connected to
output terminals, and output terminals to input terminals. Control system parts areconnected in the same way as electrical-circuit parts. As an example, place a ‘constant’part (40 Control function block) and an ‘initial value’ part (42 Control function block)onto the canvas.

1.

Click the (blue) output terminal of the constant part (FIX1). The mouse cursor
then changes to a plus sign (+), indicating the program has switched from ‘partselection’ mode to the mode for automatically creating control system wires. (Toswitch to this mode manually, select ‘Control system wire’ from the ‘Circuit’
menu.) Connect the control system wire to the (orange) input terminal of theinitial value part (INIT1) in the same way as when making a node connection.

2.

Once the wire has been connected correctly, the blue and orange boxes
indicating the terminals disappear. An arrow indicating the wiring direction isdisplayed at the input terminal.

- 39 -

5.4

Control system wire properties

Double-clicking on a wire displays its ‘properties’ screen.

DisplayThis screen is used to enable or disable the display of the control-system wire nameon the circuit-diagram canvas. Checking the checkbox in this tab displays the name of
the wire name on the canvas. Since the control-system wiring represents the controlblock connections, the wires have no associated values, and therefore do not have a‘Recording’ tab.

5.5

Creating multiple-signal control system wirings

This section describes multiple-signal control system wirings (vectors) that group
together multiple control signals. Basic operations are same as for a single-signal
control system wiring.
First, create a vector signal including three elements from three single signals(conventional control signals). Place any three single signals on each (in this case,‘constant’ [42 Control function block] and ‘vector creation’ [46 Special function function
block]).

1.

Next, double-click the part ‘vector creation (MTINP1)’ to open the properties
screen, and change the number of elements to 3.

- 40 -

2.

Next, click the constant (FIX1) output terminal (blue). The mouse cursor will turninto a ‘+’, and the mode will automatically change from the part selection modeto the control system wiring creation mode. After this, wire the control systemwiring to the ‘vector creation (MTINP1)’ input terminal (orange) in the same way
as for the node connection. Once the wiring is properly done, the □□ of theconnected terminal will disappear, and an arrow indicating the direction of wiring
will appear on the input-side terminal.

3.

The wiring is completed once all of the single signals are connected. The outputof the part ‘vector creation (MTIPN1)’ is the vector signal. As shown in the
diagram below, the signal lines have different thicknesses.
The vector signal line can only be connected to the vector signal line’s terminal(the thick □□).
Also note that parts that can handle the vector signal have “vector” at the front of
their part names.

- 41 -

4.

To only isolate one element from the vector signal line, use ‘Vector element value
output’ (46 Special function function block). Here we will isolate the second
signal from the previously created vector signals.
First, place ‘vector element value output’ on the canvas.

5.

Next, double-click the part ‘Vector element value output (MTOUT1)’ to open its
property screen, and input 2 (half-width digit) as the output element number.

6.

Finally, connect ‘Vector creation (MTIN1)’ and ‘Vector element value output(MTOUT1)’. The output of MTOUT1 becomes a single signal.

- 42 -

5.6

Creating three-phase buses

A three-phase bus enables three phases of electrical circuit wiring to be connected toa single wire (bus).

1.

Select ‘Three-phase bus’ from the ‘Circuit’ menu in the main window. The mouse
cursor changes to a plus sign (+), indicating that the program has entered themode for creating a three-phase bus.

2.

Click the circuit-diagram canvas and move the mouse straight downward. A line
is drawn, thicker than a connection line.

3.

To change the drawing direction from vertical to horizontal, click at the desired
location. The bus changes direction at the click location.

- 43 -

4.

The example below describes how to connect a three-phase power source andpower-transmission line with two parallel lines to a single bus. For simplicity, thetransmission line is implemented as resistors.

02 Sine wave voltage source
From the category ‘02 Sine wave voltage sources – 00 Independent voltage
source/current sources’ in the ‘part category’ box, select and place a ‘02 Sine wave
voltage source’. Create three of these parts on the left side of the bus. From the partmenu, select ‘Figure – Rotate 90 degrees right’ to rotate the parts.
00 Resistor (linear)
From the category ‘01 RLCs’ in the ‘part category’ box, select and place ‘00 Resistor(linear)’. Create six of these parts on the right side of the bus.
5.

Connect the ‘02 Sine wave voltage source’ part and the bus. Perform the same
operation for creating a wire to connect the right terminal of the ‘02 Sine wave
voltage source’ part to the bus.

6.

Move the mouse cursor to the bus and double-click.

7.

If the connection is successful, a window for selecting the wire name appears.

- 44 -

[Wire name:]
The letters ‘a’, ‘b’ and ‘c’ indicate phases a, b and c. Select which phase to connect
the wire to.
[Connection wire name:]
This field displays the connection wire name. ‘Wire name’ shows the phase, while‘Connection wire name’ shows the name of the wire actually connected.
8.

To connect to phase a, select ‘a’ as the wire name and click ‘OK’. The programautomatically assigns the connection wire name. This name is displayed to
identify the wire. To erase the name, uncheck the [Display] checkbox in the node
properties.

9.

Repeat Steps 6 and 7 to connect the second ‘02 Sine wave voltage source’ partto the bus.

10. If the connection is successful, the window for selecting the wire name appears.
To connect to phase b, select ‘b’ as the wire name. If phase a is selected, it will
be shown to be already connected to a different wire.
11. Repeat the above operation to connect the ‘00 Resistor (linear)’ parts to the bus.
When R1 is connected to the three-phase bus, the window for selecting the wirename appears. In the example below, ‘a’ is selected to connect it to phase a.
12. Repeat the above steps for the other resistors, connecting R4 to phase a, R2
and R5 to phase b, and R3 and R6 to phase c.
The two circuit diagrams below depict equivalent circuits.

Equivalent- 45 -

13. To change the length of a previously created three-phase bus, switch to the‘three-phase bus’ mode, and click on one end of the bus. Drag the mouse in thedesired direction to extend the bus to the desired length. One bend in the bus isdeleted at each right-click of the mouse.

Click end

14. Buses are also assigned unique names. To display the name of a bus, doubleclick on the bus to display its properties. Check the checkbox in the [Display] tab
to display its name. When performing a power-flow calculation, the bus name isthe name of the connection node used for the parts that appear in the calculation.

- 46 -

5.7

Creating line concentrators

Line concentrators allow the drawing of multiple connection lines as a single line. There
are two types of line concentrators: electrical circuits are displayed as thick black lines,
and control systems are displayed as thick blue lines (in versions up to Ver. 2.01,
electrical circuit N-line concentrators were thick blue lines, and control circuit N-line
concentrators were thick green lines). Also, the number of signals included in a wiring
is shown at that wiring’s edge (‘N = *’). The required line-concentrator type depends on
the part type, but the connection method and operations are the same. Also note thatwhen calculating power flow, it is necessary to use a “three-phase bus,” not an“electrical circuit N-line concentrator.”
Electrical circuit
N-line concentrator

Control circuit
N-line concentrator

Example of electrical circuit N-line concentrator use
1.
2.

Select ‘Electrical circuit N-line concentrator’ from the ‘Circuit’ menu in the main
window. The mouse cursor changes to a plus sign (+), indicating the program
has switched to the ‘electrical circuit N-line concentrator’ mode.
Click on the circuit-diagram canvas, and move the mouse straight downward. A
line is drawn, thicker than an electric circuit wire.

3. Click the mouse to change the drawing direction from vertical to horizontal. Then,move the mouse cursor to the right.

- 47 -

4.

Click the mouse again to change the drawing direction back to vertical. Movethe mouse upwards. Double-click to complete the line concentrator. After theline is placed, ‘N = 2’ will appear on the edge of the line as the number of line
concentrators (two by default).

5.

Place parts as shown below.

02 Sine wave voltage source
From the category ‘02 Voltage source/current sources – 02 Independent voltage
source/current sources’ in the ‘part category’ box, select and place an ‘02 Sine wave
voltage source’. Create and place four of these parts on the left of the line
concentrator. From the part menu, select ‘Figure – Rotate 90 degrees right’ to rotate
the parts.
00 Resistor (linear)
From the category ‘01 RLCs’ in the ‘part category’ box, select and place ‘00 Resistor(linear)’. Create and place four of these parts on the right of the line concentrator.
6.

Connect the ‘02 Sine wave voltage source’ part and the line concentrator.
Perform the same operation used when creating a wire, to make a connection
from the right terminal of the ‘02 Sine wave voltage source’ part to the line
concentrator.

7.

Move the mouse cursor to the line concentrator and double-click.

8.

If the connection is successful, a window for selecting the wire name appears.

- 48 -

Wire name
Select the names of the wires controlled by the line concentrator. A wire name isadded each time the ‘Add wire’ button is clicked. Since the purpose is to make an Nphase connection, the wire names will be 1, 2, 3, ...N. To delete unneeded wirenames, right-click on the line concentrator and select ‘Reassign numbers’.
Connection wire name
This command displays the name of the connection wire. ‘Wire name’ shows thephases, while ‘Connection wire name’ shows the name of the wire actually connected.

- 49 -

9.

To connect to the first node, select ‘1’ as the wire name, and click ‘OK’. The
connection-wire name is displayed, identifying the wire. To erase the name,uncheck the [Display] checkbox in the properties.

10. Repeat Steps 6 and 7 to connect the second ‘02 Sine wave voltage source’ partto the line concentrator.
11. If the connection is successful, a window for selecting the wire name appears.
To connect to wire 2, select ‘2’ as the wire name.
12. Repeat Step 10 to connect the remaining ‘02 Sine wave voltage source’ parts tothe line concentrator.

- 50 -

Equivalent

13. Repeat the above operation to connect the ‘00 Resistor (linear)’ parts to the line
concentrator. Connect the ‘00 Resistor (linear)’ parts R1, R2, R3, and R4 to 1,
2, 3, and 4, respectively. The two circuits diagrams below are equivalent.

- 51 -

6

Analysis Processes

XTAP performs transient analysis (instantaneous-value analysis) and has a steadystate initialization function to enable the transient analysis to start from the circuit’s
steady-state condition. Either of two methods can be used for steady-state initialization:
one defines the initial values of the dynamic-circuit elements by calculating the AC
steady-state solutions; in the second, the initial values are set using a power-flow
calculation to determine the steady-state condition of the generator and loads, andhence use the result to calculate the AC steady-state solutions.
There are four types of XTAP analyses:① Transient analysis② Steady-state initialization → Transient analysis③ Power-flow calculation → Steady-state initialization → Transient analysis④ Frequency-characteristic calculation (frequency scan)
Each type of analysis is described below.
① Transient analysis
This performs a standard analysis of instantaneous values, starting from a state where
the power-source voltage or current is zero.
② Steady-state initialization → Transient analysis
The program calculates the AC steady-state solution, considering the unbalanced
circuit conditions. Using these results as initial values, the analysis starts from thesteady-state operation condition. This type of analysis specifies a negative value forthe ‘Start time’ parameter for the sine and cosine wave voltage/current sources, toinclude them in the AC steady-state calculation. Power sources with waveforms otherthan sine or cosine are ignored in the AC steady-state calculation.
③ Power-flow calculation → Steady-state initialization → Transient analysis
The program uses a power-flow calculation (the ‘L method’) to determine the steadystate solutions, ignoring harmonics or unbalanced circuit conditions. The solutions areused to analyze the AC steady-state solution to find approximations, considering
unbalanced circuit conditions. These results are then used as the initial values foranalysis away from the steady-state operation condition. ‘Power-flow calculation
auxiliary parts’ are used to specify the power-flow conditions.
④ Frequency-characteristic calculation (frequency scan)
Analysis types ① to ③ are ultimately time-domain calculations (transient analyses).
This calculation returns results in the frequency domain. The frequency f is varied withina specified range, and an AC steady-state calculation is performed repeatedly todetermine the corresponding change in value. This type of analysis specifies a negativevalue for the ‘Start time’ parameter for sine and cosine wave voltage/current sources,
so that these power sources may be considered in the AC steady-state calculation.
Power sources with waveforms other than sine or cosine are ignored in the AC steadystate calculation.

- 52 -

6.1

Analysis settings

Conditions must be set to perform analyses. To do this, select ‘Analysis settings’ fromthe ‘Analysis’ menu in the main window. The method for setting analysis conditions is
described in the procedure relevant to each analysis process.

- 53 -

6.2

Analysis procedure (analysis type: transient analysis)

This section describes how to execute a standard transient analysis. As an example,
we illustrate the analysis process using the PE-01.xsf file provided with XTAP.
1.

Select ‘Open’ – ‘Open circuit diagram’ from the ‘File’ menu in the main window,
and select ‘PE-01.xsf’ from the ‘Open file’ screen. The PE-01.xsf file is locatedin work/templates/PE-01, in the folder where XTAP was installed.

2.

The following circuit diagram is then displayed.

3.

Select ‘Analysis settings’ from the ‘Analysis’ menu in the main window, or click
the corresponding toolbar button.

- 54 -

4.

The analysis settings screen appears.

1 Analysis-file save location
Specify the analysis filename (*.xtf file) and the save location. When the savelocation is specified as a relative path, this path is assumed to be expressed
relative to the location of the circuit diagram file (*.xsf file). When the savelocation is specified as an absolute path, this path is used as the save location.
2 Analysis-type selection
Select the analysis type. In this example, ‘Transient analysis’ is selected.
3 Analysis conditions
Specify the analysis conditions corresponding to the analysis type.
Case name:Specify the name of the analysis case. This will be used as the title when
the analysis is graphed in XPLT.
Calculation time increment:
Specify the calculation time increment (Δt).
Calculation end time:
Specify the calculation end time.
BNR switching iteration count:
Specify the number of iterations for switching the convergence calculationfrom the standard Newton-Raphson method to the biaxial NewtonRaphson method (this setting usually does not need to be changed).
Katzenelson switching iteration count:
Specify the number of iterations for switching from the biaxial NewtonRaphson method to the Katzenelson method (this setting usually does notneed to be changed).
Calculation result output file:Specify the calculation output file name. By default, the save location is arelative path starting from the location of the circuit diagram file (*.xsf file).
- 55 -

When the save location is instead specified as an absolute path, this isthen used as the save location.
Output start time:
Specify the time at which to start collecting the calculation output.
Output end time:
Specify the time at which to end collecting the calculation output.
Output frequency:
Specify the output sampling rate.
Text format/CSV format calculation result output:
Specifying ‘Yes (text format)’ outputs calculation results in text format(space-separated). Specifying ‘Yes (CSV format)’ outputs results in CSV
format (comma-separated).
Text format output file:Specify a file name when the calculation output is in text format. The savelocation is specified relative to the location of the circuit diagram file (*.xsffile). When the save location is specified as an absolute path, this path isthen used as the save location.
CSV format output file:Specify a file name when outputting calculation results in CSV format. The
save location is a path specified relative to the location of the circuit
diagram file (*.xsf file). When the specified save location is an absolutepath, this path is used as the save location.
Debugging level:
Specify the debugging level. This setting is not normallyused by the user.
5.

Click the OK button in the screen.

6.

Save the circuit, then perform the analysis by selecting ‘Run analysis’ from the‘Analysis’ menu or by clicking the corresponding toolbar button. The analysis
cannot execute if the circuit has been changed. (The ‘Run analysis’ menu item
and corresponding toolbar button are then inactive and cannot be selected).

7.

The command prompt is displayed when the analysis is executed.

- 56 -

When the analysis ends normally, the message ‘Analysis complete’ appears.

8.

An error message is displayed if the analysis process ends with an error. If
source of the error is in the circuit, the error message is output and displayed in
the file ‘xcoremsg.out’. If the error originates from the control block, the error
message is output and displayed in the file ‘dynamsg.out’. The message file isoutput to the save location of the analysis file (*.xtf file).

- 57 -

6.3

Analysis procedure (analysis type: steady-state
initialization → transient analysis)

This section describes how to perform a steady-state initialization by calculating AC
steady-state solutions. As an example, we illustrate the analysis process using the
SSW-01.xsf file provided with XTAP.
1.

Select ‘Open’ – ‘Open circuit diagram’ from the ‘File’ menu in the main window,
and select ‘SSW-01.xsf’ from the ‘Open file’ screen. The SSW-01.xsf file islocated in work/templates/SSW-01, in the folder where XTAP was installed.

- 58 -

2.

Sets the parameters for steady-state initialization. Double-click the SIN wave voltage
source to open the parameter setting window. To perform steady-state initialization, set“Start time” to a negative value in the parameter settings (any negative values areallowed).

Enter negative
value

3.

Select ‘Analysis settings’ from the ‘Analysis’ menu in the main window.

4.

The analysis settings screen then appears.

- 59 -

1 Analysis file save location
Specify the analysis filename (*.xtf file) and the save location. The default
setting is [Circuit diagram file name] + .xtf. When the save location is specified
as a relative path, this path is assumed to be expressed relative to the locationof the circuit diagram file (*.xsf file). When the save location is specified as an
absolute path, this path is used as the save location.
2 Analysis type selection
Select the analysis type. For this example, select ‘Steady-state initialization →Transient analysis’ .
3 Analysis conditions
Specify the analysis conditions corresponding to the analysis type. All the items
other than the three below are the same as for the transient analysis.
System frequency:
Specify the system frequency. This must be the same as the frequency ofthe power source in the circuit. A warning is output if the circuit contains asine- or cosine-wave power source with a frequency different from this set
frequency.
Output power flow/steady-state analysis result output file:
Setting ‘Yes’ outputs the steady-state analysis results.
Power flow/steady-state analysis result output file:Specify a file name when outputting the steady-state analysis results. The
default setting is [Circuit diagram file name] + _PFSS.txt. When the savelocation is specified as a relative path, this path is assumed to be
expressed relative to the location of the circuit diagram file (*.xsf file). Whenthe save location is specified as an absolute path, this path is used as the
save location.
5.

Click the ‘Start calculation’ button on the screen.

6.

The command prompt is displayed when the analysis process is executed.

When the analysis process ends normally, the message ‘Analysis finished.’ appears.

- 60 -

The results of the AC steady-state calculation are output as a text file. The AC
steady-state solutions of the variables specified in the ‘Recording’ tab are output.

- 61 -

6.4

Analysis procedure (analysis type: power flow
calculation → steady-state initialization → transient
analysis)

This section describes how to perform a steady-state initialization by calculating AC
steady-state solutions, with steady-state conditions applied to the generators and loads,
as determined by power-flow calculation (the ‘L method’). The steady-state initialization
workflow is as follows:① Create the circuit diagram (a three-phase bus).
↓② Specify the power-flow conditions using power-flow-calculation auxiliary parts.
↓③ Set information-acquisition flags for the power-flow calculation using macro parts.
↓④ Execute the analysis.
① Create circuit diagram
The circuit diagram is created with the usual procedure, but the nodes and branches
used to set initial values (synchronous generators or user-created macro parts) must
be connected to a three-phase bus. See Section 5.6 for details of how to connect athree-phase bus.
② Specify the power flow conditions using power-flow-calculation auxiliarypartsSpecify the power-flow conditions for each bus using power-flow-calculation auxiliaryparts. These parts are located in the ‘20 Power flow calculation/steady-state
initialization auxiliary parts’ section of the part category window. Use these parts toenter the initial values specified in the power-flow calculation. A power-flow-calculation
auxiliary part should be connected to phase A of a three-phase bus. The reference
capacity is specified in Step 4. This capacity is not the reference capacity for individual
devices, and therefore care is needed when setting parameters.
③ Use macro parts to set flags for acquiring power flow calculation information
When connected to a three-phase bus, the following parts can use the results of apower-flow calculation (power-flow-calculation information) as parameters:
Parts that can acquire power-flow-calculation information
01 RLC¾ 12 RX Parallel load model (single-phase)¾ 13 RX Parallel load model
07 Generator
00 Synchronous generator¾ 00 Synchronous generator (d1, q1, accounting for magnetic saturation)¾ 01 Synchronous generator (d1, q2, accounting for magnetic saturation)¾ 02 Synchronous generator (d1, q1)¾ 03 Synchronous generator (d1, q2)¾ 04 Synchronous generator (d1, q1, accounting for magnetic saturation and axis
torque)¾ 05 Synchronous generator (d1, q2, accounting for magnetic saturation and axis
torque)¾ 06 Synchronous generator (d1, q1, accounting for axis torque)¾ 07 Synchronous generator (d1, q2, accounting for axis torque)07 Generator¾ 00 Infinite bus generator- 62 -

99 User's Components¾ (Arbitrary macro part)
The part properties for the synchronous generators and infinite bus generators do nothave a tab for power-flow-calculation information acquisition; this function is enabled
by default. For arbitrary user-created macro parts, the choice to use power-flowcalculation information can be set in the power-flow-calculation information tab.
Parts that acquire power-flow-calculation information operate as follows:(1) During steady-state initialization, the part is removed from the three-phase bus.
※1 When the generator bus of an auxiliary component for the power-flow calculation (slack
generator bus, PV generator bus, PQ generator bus bar) is connected to the three-phasebus, a three-phase voltage source with the voltage and phase according to the powerflow calculation result of the bus is automatically added.
※2 When the load bus of an auxiliary component for the power-flow calculation (PV loadbus, PQ load bus) is connected to the three-phase bus, the three-phase load with thevoltage and phase according to the load flow calculation result of the bus is automatically
added.
※3 The “13 RX parallel load model” cannot be removed from the three-phase bus in thesteady-state initialization calculation. Therefore, when the load bus of the auxiliarycomponent for power-flow calculation is connected to the three-phase bus, both the RX
parallel load model and the automatically-added three-phase load are considered in thesteady-state initialization calculation. Therefore, if you want to remove the load modelfrom the three-phase bus, please use “14 RX parallel load model (exclude enabled)”
instead of “13 RX parallel load model”.
(2) The following variables (parameters) can be used in the parameter fields andformula fields of part properties. The value is acquired from the three-phase bus
to which the part is connected.
Vbus
Bus voltage [V]theta_bus Bus voltage phase [rad]PGbus
Bus generator active power [W]
QGbus Bus generator reactive power [var]PLbus
Bus load active power [W]
QLbus
Bus load reactive power [var]theta_shifted Phase difference from bus voltage reference phase [deg]CautionFor synchronous generators and infinite bus generators, power-flowcalculation information acquisition is enabled by default (and cannot bedisabled). Problems such as information not being considered during steadystate initialization, or initialization not being performed properly, can therefore
occur when an analysis is performed without executing a power-flow
calculation. When using these parts, the analysis type should therefore be set
to the type that includes power-flow calculation.

- 63 -

④ Execute analysis
Execute the analysis once the circuit has been created using Steps 1, 2, and 3.
Below is an example of a power-flow calculation, steady-state initialization, andtransient analysis using one of the templates (MAC-01) provided with XTAP.
1.
2.

From the ‘File’ menu in the main window, select ‘Open circuit’. Then, select‘MAC-01-A.xsf’ from the ‘Open file’ screen. The file MAC-01-A.xsf is located inbin/work/templates/MAC-01, in the folder where XTAP is installed.
The circuit diagram below then appears.

3. Specify the generator power-flow conditions.
Specify the conditions to be applied during the steady-state operation of thegenerator for the power-flow calculation. From the ‘part category’ window, select anduse the part ‘07 Generator 00 synchronous generator’ in combination with either thepart ‘20 Power flow calculation/steady-state initialization auxiliary parts － 01 PV
specification generator bus’ or ‘02 PQ specification generator bus’. The template isdesignated ‘PV’, specifying the generator output and generator terminal voltage.

- 64 -

4. Set the power-transmission-line impedance.
Specify the impedance of the power-transmission line to be considered during thepower-flow calculation. This calculation considers only the portions with a positive
phase, and therefore only these portions can be specified in the parameters.

Use the part ‘06 Line branch’ for a power-transmission line, and ‘07 Transformer
branch’ for a transformer.
5. Set the reference generator bus.
One reference generator bus must be set. The part ‘07 Generator － 02 Infinite bus
generator’ is normally used, combined with ’20 Power flow calculation/steady-state
initialization auxiliary part － 00 Reference generator bus’.

- 65 -

6.

Select ‘Analysis settings’ from the ‘Analysis’ menu in the main window.
The analysis settings screen appears.

1 Analysis-file save location
Specify the analysis file (*.xtf file) name and the save location. The default
setting is [Circuit diagram file name] + .xtf. When the save location is specified
as a relative path, this path is assumed to be expressed relative to the locationof the circuit diagram file (*.xsf file). When the save location is specified as an
absolute path, this path is used as the save location.
2 Selecting the analysis type
Select the analysis type. For this example, ‘Power-flow calculation → Steadystate initialization → Transient analysis’ is selected.
3 Analysis conditions
Specify the analysis conditions corresponding to the analysis type. All the items
other than the following are the same as for the ‘steady-state initialization →transient analysis’ process.
Reference capacity:
Specify the reference capacity of the system. Note that this figure is not thereference capacity for each device.
7.

Click the ‘Start calculation’ button on the screen.

8.

The command prompt is displayed when the analysis is executed.

- 66 -

When the analysis ends normally, the message ‘Analysis complete’ appears.

The results of the power-flow calculation are output as a text file. They can be used
to check that the initial values specified in Steps 3 to 5 were used.

9.

An error message will be shown when an error occurs during the execution of
the simulation.When the error is related to the circuit part, the details of theerror will be displayed in the file “xcoremsg.out”. When the error is related tothe control-system part, the details of the error will be displayed in the file“dynamsg.out”. When the error is related to the power-flow calculation, thedetails of the error will be displayed in the file “flowmsg.out”. All these file arelocated in the same folder of the simulation .xtf file.

- 67 -

6.5

Analysis procedure (analysis type: frequency
characteristic calculation)

The frequency-characteristic calculation is a function that calculates the response to achange in a power-source frequency in a circuit, between user-specified start and end
values, in arbitrary increments.
Consider a simple RLC series circuit as an example.
1. Create a series circuit consisting of a power source, resistance, inductance, and capacitanceas shown in the figure below.

The calculated frequency characteristic is that produced by the power source ‘E_cos1’.
Usable power sources may be of one of the following four types. Other power sources
are treated as short-circuited (voltage sources) or open (current sources) in the context
of the calculation. The usable power sources will also be treated as short-circuited(voltage sources) or open (current sources) if the setting described in Step 2 (enteringa negative start time) is not entered.
Sine wave voltage source
Sine wave current source
Cosine wave voltage source Cosine wave current source
2. Set the parameters for the frequency-characteristic calculation.
Double-click the power source to open the ‘parameter setting’ screen. Set ‘Start time’to a negative value (any negative value is acceptable) to cause this power source tobecome recognized as the power source for implementing frequency variation.

Enter negative value- 68 -

3.

Select ‘Analysis settings’ from the ‘Analysis’ menu in the main window.
The analysis settings screen appears.

1 Analysis file save location
Specify the analysis filename (*.xtf file) and the save location. The default
setting is [Circuit diagram file name] + .xtf. When the save location is specified
as a relative path, this path is assumed to be expressed relative to the locationof the circuit diagram file (*.xsf file). When the save location is specified as an
absolute path, this path is used as the save location.
2 Analysis type selection
Select the analysis type. For this example, select ‘Frequency characteristic
calculation (frequency scan)’.
3 Analysis conditions
Specify the analysis conditions corresponding to the analysis type.
Case name:Specify the analysis case name. This name is used as the title when theanalysis is graphed in XPLT.
Start frequency:
Specify the starting frequency for the frequency-characteristic calculation.
End frequency:
Specify the end frequency.
Frequency count:
Specify the number of frequencies at which to perform the calculation
between the start and end frequencies.
Frequency sampling:Specify whether to use equal (linear) or log-scale sampling intervals.

- 69 -

Calculation result output file:Specify the output file name. When the save location is specified as arelative path, this path is assumed to be expressed relative to the locationof the circuit diagram file (*.xsf file). When the save location is specified as
an absolute path, this path is used as the save location.
Text format/CSV format calculation result output:
Specifying ‘Yes (text format)’ outputs the calculation results in text format(space-separated). Specifying ‘Yes (CSV format)’ outputs them in CSV
format (comma-separated).
Text format output file:Specify a file name when outputting calculation results in text format. Whenthe save location is specified as a relative path, this path is assumed to be
expressed relative to the location of the circuit diagram file (*.xsf file). Whenthe save location is specified as an absolute path, this path is used as the
save location.
CSV format output file:Specify a file name when outputting calculation results in CSV format.
When the save location is expressed as a relative path, this path isassumed to be expressed relative to the location of the circuit diagram file(*.xsf file). When the save location is specified as an absolute path, thispath is used as the save location.
Debugging level:
Specify the debugging level. This setting is not normally used by the user.
4.

Click the ‘Start calculation’ button on the screen.

5.

The command prompt is displayed when the analysis process is executed.

When the analysis process ends normally, the message ‘Analysis finished’
appears.

- 70 -

6.6

Files related to analysis processes

This section describes the files used for analyses (*.xsf files) and those generated byanalysis processes.
*.xsf (XTAP schematic file) files
These binary files store circuit diagrams to be analyzed.
*.xpf (XTAP plot file) files
These binary files store the analysis results. They can be used to display graphs with
XPLT.
xcoremsg.out
This file contains errors and warning messages, generated during analysis, that relate
to circuit areas. Generated errors are displayed automatically on the screen, but
warnings unaccompanied by errors are not displayed automatically, and therefore
require caution.
dynamsg.out
This file contains errors and warning messages, generated during analysis, that relate
to control-block areas. Generated errors are displayed automatically on the screen, but
warnings unaccompanied by errors are not displayed automatically, and therefore
require caution.
flowmsg.out
The details of errors and warnings related to the power-flow calculation will be savedin this file. Errors will be automatically displayed in the screen when executing thesimulation, however warning will not be automatically displayed.
*.xtf (XTAP text file) files
Text-format input data files that are generated from *.xsf files by the XTAP graphicaluser interface, and are read by the XTAP analysis program.#*.xmf (XTAP model file) files
These files specify models (macro parts) included by *.xtf files. Like *.xtf files, *.xmf
files are text files generated from *.xsf files by the graphical user interface.#*.xtf.pp (XTAP text file preprocessed) files
These files are generated by the XTAP analysis program as intermediate process
outputs.#
Normally .xpf files, .hmtl files, .xtf files, .xmf files and xtf.pp files are located in the same
folder as the .xsf schematic file. However, the location of .xpf files and .xtf files can bechanged by changing options in the simulation setup.
#Users do not need to reference these files.

- 71 -

6.7

Search function

The search function can be used to find parts or other elements in a circuit diagram.

Select ‘Search’ from the ‘Circuit’ menu or click the corresponding toolbar button to open
the search screen.

1
2

3

4

5

Search-screen items:
1 is used to enter the target text string;
2 starts the search;
3 closes the window;
4 makes the search case-sensitive when this checkbox is selected;
5 lists the search results. Clicking a ‘Path name’ entry selects that part or element.
If the selected search result is located within a macro part, the circuit diagram ofthat macro part opens to show the result.

- 72 -

7

Consecutive-Analysis Function

7.1

Overview of consecutive analysis function

This function uses parameter settings derived from values such as analysis-circuit
element values. The function calculation involves consecutively varying the parametervalues. In addition, XTAP also has another function for calculating statistical switchingsurges (described in Chapter 8).

7.2

Opening the consecutive-analysis settings window

The setting for the consecutive-analysis can be made in the consecutive-analysis settings
window. Select “Consecutive-Analysis Settings” from “Analysis” in the main menu. Or click
the “Consecutive-Analysis Settings” icon in the toolbar.

- 73 -

7.3

Consecutive-analysis settings window

This section describes the consecutive-analysis settings window. An example is shownin the following screenshot.

2

1

4
6

5

3

8

7

9

11

10

1. General settings tab• used to set consecutive analysis.
2. Statistical switching-surge calculation settings tab• used to set the statistical switching-surge calculation function (described in Chapter
8).
3. Matrix-size menu
• used to specify the number of cases to be executed consecutively and the number ofparameters to set. The data input screen changes according to the values specified
here. Up to 1,000 cases and up to 100 parameters can be specified. The analysis canstill proceed even if some of the specified cases and parameters are left blank.
4. Run all/stop all menu
• It is possible to select at once cases that will be executed and cases that will be
stopped. By clicking on “Run all” all cases will be set to be executed. By clicking on“Stop all” all cases will be set to be stopped. Moreover, when selecting some casenumbers (refer the item 10 shown below), this menu will be automatically changed to“Run Selected Cases” and “Stop Selected Cases”
5. Analysis result process menu
• contains the buttons used to run and set statistical processes (operations acquiringvalues such as the waveform maximum or average values), executed on multipleanalysis results (described in Section 7.8).
6. Close menu
• closes the window. Clicking ‘OK’ closes the window with the entered settings applied.
Clicking ‘Cancel’ closes the window without applying the changes.
7. Formula area

- 74 -

• displays the parameter input cell information. This area can also be used to input
numerical values and formulas to be provided as parameters directly.
8. Case number button• This button is used to select several cases at once. It can be used to setting to run or
to stop several cases at once, for example. It is also possible to selected cases byusing the Ctrl or Shift keys.
9. Run/stop selection button• determines whether or not each case will be executed in a consecutive analysis.
10. Parameter name input cells• used to enter parameter names (variable names).
11. Parameter input cells• used to enter the numbers and formulas required as parameters.

7.4

Setting the number of cases and of parameters

Use the ‘matrix size’ menu to specify the number of cases and of parameters to executeconsecutively. The number of parameter-setting cells then changes to match thespecified number of cases and parameters.

- 75 -

7.5

Parameter input method

1. The properties normally entered as values are entered as variables. In theexample below, the voltage-source voltage is set as the parameter ‘Param_A’.

Most of the properties (e.g., voltage, current, frequency, resistance, inductance, andthe ‘switch ON’ time) of parts (e.g., power sources, resistors, and switches) can be set
as parameters. However, note that variable names cannot be used for some properties,
such as initial values (e.g., the initial current in an inductor or the initial voltage of acapacitor), file names of parts that reference external files, and properties of powerflow-calculation auxiliary parts.
● All properties that can be used as macro-part parameters are permitted.
● Only alphanumeric characters (uppercase letters, lowercase letters or numbers) andunderscores “_” can be used for the parameter names.
● Note that auxiliary units (prefixes for units of measurement such as M, k, m, or μ) forvalues set as parameters in the properties input screen are ignored.
● Note that a normal analysis is no longer possible if part-property parameters are set
in order to run consecutive analysis (since values are not input for variables enteredas parameters).

- 76 -

2. Enter the parameter name in the ‘Parameter name’ field.

3. Enter the parameter value for each case.

- 77 -

Entering parameter values can be facilitated by copying the data sets for multiple cases
from a spreadsheet program such as Excel, and pasting them into XTAP.

A parameter or data-list information
created in Excel can be copied andpasted as a block of multiple cells.

- 78 -

Parameter values can be entered using a formula syntax. The information in theformula area or a cell is interpreted as a formula when its first character is an ‘equals’
sign (=). Cells are referenced in R1C1 format.
A reference in R1C1 format is entered as follows. A relative cell reference to the cellthat is located one cell to the left of the current cell is written ‘RC[-1]’, where ‘R’ stands
for ‘row’ and ‘C’ for ‘column’. The brackets [ ] specify the number of steps separating
the referenced cell from the current cell, in the horizontal or vertical direction. Specifying‘R’ (row) without a number in brackets means that the referenced cell is in the samerow as the current cell. ‘R[-1]’ signifies ‘one row up’, and ‘R[1]’ means ‘one row down’.
Similarly, ‘C’ (the column), specified without a number in brackets, signifies that thereferenced cell is in the same column as the current cell, ‘C[-1]’ signifies ‘one column
to the left’, and ‘C[1]’ means one column to the right. Absolute cell references are
specified without brackets. For example, ‘R1C1’ denotes the cell of the first row andfirst column.

- 79 -

Entering an ‘equals’ sign (=) in the formula area followed by a letter or text string
displays a list of functions starting with the entered text. (Hovering the mouse cursor
over the name of a function displays a tooltip with brief help information for thatfunction.)

7.6

Ending/canceling parameter settings

When the parameter settings have been entered, click ‘OK’ in the ‘Close’ menu to apply
the changes to the analysis circuit. (An analysis cannot be executed without first saving
the circuit.) To cancel the editing of parameter input cells, click ‘Cancel’. The ‘X’ button
at the top-right corner of the window performs the same operation as the ‘Cancel’ button.
When analysis is executed (described later), the process stops in the error status if aparameter cell is missing a value. However, rows and columns left completely blankare automatically ignored; no error is generated if the specified number of cases andparameters exceeds the actual number of cases and parameters provided.

Same as‘Cancel’- 80 -

7.7

Executing a consecutive analysis

After entering the analysis settings and saving the circuit, press the toolbar button
indicated below to execute the consecutive analysis.

The following message appears if a text-format calculation output has been selectedin the analysis settings. The file size may be large for such an output. To cancel ananalysis, select ‘Yes’. To output the calculation results in text format using the set
analysis settings, select ‘No’. If there is no problem, select ‘No’ to proceed with thecalculation.

The expected size of the calculation output file will be displayed. Check if there issufficient hard-disk capacity before proceeding with the simulation.

- 81 -

When the calculation starts, a message is displayed indicating the case being currently
executed. Cases for which the run/stop setting has been entered as ‘Stop’ are notexecuted.

The following message appears when the analysis of all the cases has finished.

The following files are then generated:
Analysis file name_(case number).xtf• input data files (one for each case) in text format.
Analysis file name_(case number).xtf.pp• files generated by the XTAP analysis program as intermediate process outputs.
AUTOSUB.xmf• a data file containing the created circuit data in the form of macro parts (sincemacroing is required for using parameters).
Analysis file name_(case number).xpf• binary files storing the analysis results (one file for each case).
Analysis file name_all.csv• a file that contains the analysis results, and the file name and time for each case.
These analysis results are used when performing statistical processes.

- 82 -

7.8

Statistical processes for analysis results

The recorded waveform results of a consecutive analysis carried out on a set of cases
can be loaded into XTAP to determine the following quantities:¾ Maximum (MAX)¾ Minimum (MIN)¾ Maximum absolute value (MAXABS)¾ Average (AVE)¾ Integral (INTEGRAL)¾ Effective value (RMS) (Frequencies are set in the PostProcessing.ini file.)● The PostProcessing.ini file is stored in the folder containing xgui.exe (normallyC¥XTAP¥bin).
The format used for writing values is as follows:[PostProcessingSection]
HZ=50

In addition to the six above quantities, operations on the recorded waveforms can be
implemented using DLL files, as required by the user. For details, see Appendix 3 inthis manual, “Creating and Using DLL Files for Statistical Processes.”- 83 -

7.9

Executing statistical processes

Statistical processes are executed from the ‘analysis-result process’ menu in the‘consecutive-analysis settings’ window.

(1) Consecutive processing of analysis results

Press the ‘analysis-result consecutive processing’ button to open the following screen.
Select the file ([File name] + ‘all.csv’) containing the file names for all the waveform
data, and click the ‘Open’ button. This operation can also be performed by doubleclicking on the file name.

- 84 -

Statistical processing is executed on each waveform file.

The following window then appears, asking whether or not the calculation result files
are to be deleted. Click ‘Yes’ to delete the files, or ‘No’ to retain the files, for example tocreate graphs.

The statistical-process result files (*.csv) are output to the folder where the calculation
was executed. The file containing the maximum-value (MAX) results is named[Analysis file name] + ‘_MAX.csv’. The files for the other results are named in a similar
fashion.

Files output by statistical processing calculations- 85 -

The information contained in the file is shown below. This comprises the calculation
results (one data item per waveform) for the analyzed waveforms, i.e., the waveforms
that were selected for recording by ticking the appropriate checkbox and that were
output to the *.xpf files.

(2) Process settings

Pressing the ‘process settings’ button opens the following window. Enter the process
type, 32-bit DLL file name, 64-bit DLL file name, and function name. Particular DLL filenames can be selected via the ‘Browse’ button.

- 86 -

In XTAP, the two dll files “PostProcessingLibrary32.dll” and “PostProcessingLibrary64.dll”
are installed by default. They contain the six operations listed previously: maximum(MAX), minimum (MIN), maximum absolute value (MAXABS), average (AVE), integral(INTEGRAL), and effective value (RMS). Accordingly, to perform any of these six
operations in statistical processing, they must be specified as shown below, to be
executed in the consecutive-processing of analysis results.

Rows, columns, and cells can be copied and pasted.
When a user-created function has been created, it can be executed by: ① entering
the analysis type name, ② specifying the created DLL, and ③ entering the function
name defined in the created DLL.

- 87 -

7.10 Displaying analysis results in XPLT
When XPLT is started after finishing statistical calculations, the calculation-result files
are not automatically selected. The calculation-result files to be displayed can beentered in XPLT using the ‘Add file’ button.

Calculation result files are not selected,
so use ‘Add file’ button to add them.

When displaying calculation results, produced by the consecutive-analysis function, in
XPLT, the specifier ‘AUTOSUB/’ is added to the element name.

- 88 -

8 Statistical Switching-Surge Calculation Function

8.1

Overview of statistical switching-surge calculation
function

The statistical switching-surge calculation function statistically analyzes the magnitudeof an input surge overvoltage by randomly varying the breaker ON timing andperforming many input-surge calculations. This analysis function automatically
performs all these calculations. Specifically, it lets the user set parameter values thatare related to the ON timing, perform many calculations automatically, and performstatistical processes on the analysis results.

8.2

Opening the settings window for a switching-surge
calculation

Open the settings window for a switching-surge calculation by selecting the ‘Statisticalswitching-surge calculation settings’ tab in the ‘case setting’ window.
4

3

1

5

6

7

2

1. Breaker-search menu
• used to search for breakers (switch parts with breaker logic) in the circuit.
2. Calculation case-count menu
• used to specify the number of calculations to perform.
3. Random number setting menu
• selects the method of determining the breaker ON command timing for each case.
The ON timing is determined from uniformly distributed random values. Either of thefollowing two methods can be selected for generating these uniformly distributed
random numbers:¾ Automatic: The seed value used to generate the random numbers is changed each time
the analysis is executed.
¾ Manual: The random numbers are calculated using a user-set seed value.

4. ON command setting menu
Using the timing from t = 0 until the fixed time T1 set here has elapsed as the reference,
the ON command timing uniformly distributes the range of cycles found from the set
power-source frequency. The random numbers in the distribution are the uniformly
distributed random numbers set in the ‘random number setting’ menu (Item 3 above).
¾ Fixed time T1: Specify the reference time for the breaker ON time.
¾ Frequency: Specify the range of values.

- 89 -

5. Analysis menu
• executes the analysis.
6. Help menu
• displays the help information (user manual).
7. Close menu
• saves the settings entered in this window upon clicking ‘OK’, or cancels them uponclicking ‘Cancel’. The ‘X’ button at the top-right corner of the window performs the same
operation as the ‘Cancel’ button.

8.3

Analysis example

This section provides an example of a statistical surge-switching calculation for thefollowing circuit consisting of three breakers.

(1) Breaker search
Click the ‘Breaker search’ button in the case setting window to search for breakers in
the circuit.

Displays names ofretrieved breakers.

- 90 -

(2) Case number specification
Specify the number of cases to calculate.

(3) Random number settingSpecify the method for calculating random numbers. When selecting the manual
method, enter a seed value.

(4) ON command settings
Enter the values for the parameters that specify the breaker ON time.

- 91 -

(5) Breaker parameter inputEnter the values for the parameters that determine the breaker ON timing.

Fixed time T2:
Standard deviation σ:
Maximum deviation σmax:

Specify the time lapse from the ON command until
the breaker operates.
Specify the standard variation in the breaker
operation time.
Specify the maximum standard variation.

The breaker operates according to the following timing.

Input command
Uniform distribution from [T1] to [T1 + 1/f)]

Actual input time
Normal distribution with standard
deviation σ, centered about [Input
command time] + T2

T2

Time

(Constant)(6) Analysis execution
Click the ‘analysis execution’ button to execute the analysis.

(7) Statistical processing of analysis results
Statistical analysis starts automatically when the analysis ends. (For the consecutive
analysis described in Chapter 7, the statistical analysis must be done manually. For
the statistical switching-surge calculation, the program proceeds to statisticalprocessing after the analysis has finished.) Click ‘Yes’ to start the statistical processing.
The analysis and output files for this processing are the same as those described in
Chapter 7. See Chapter 7 for further information.

- 92 -

9

XPLT (Graphing Program)

9.1

Starting XPLT

To start XPLT from XTAP, select ‘XPLT (graphing program)’ from the ‘Tools’ menu in themain window.

The same operation can be performed by clicking the toolbar button indicated below.

9.2

Selecting the analysis result files

When XPLT starts, an analysis result file (*.xpf file) is selected if the analysis was
executed before starting XPLT. Otherwise, or to select a different analysis result file orto add files, click ‘Add file’ and select the desired file from the ‘Open file’ window.
Note that when attempting to select an analysis-result file for which the analysis wasdone without checking the ‘Recording’ option for any part, there will be no data to output.
The message ‘No data to output’ therefore appears, and the analysis result file is notselected.
Multiple analysis-result files can be selected, enabling the data from each file to beplotted onto a single graph.

- 93 -

Calculation result executed
before starting XPLT

9.3

Displaying graphs

There are two types of graph displays: normal (plotting unmodified outputs) andmodified (plotting modified outputs). The normal graph displays are themselves of two
types: a transient-analysis graph display (with time on the horizontal axis), and afrequency-characteristic calculation graph display (with frequency on the horizontalaxis).

① Select graph result file

② Add blank graph③ Select item
④ Select output to display (one or more)⑤ Click to create graph- 94 -

(1) Normal graph display① Select a graph result file. Only one graph file can be selected.
② Click the ‘Add graph’ button to add a graph area. Do not click this button when
adding to a graph area that is already displayed.
③ Select the item to display.
④ Select the output to display. Multiple outputs can be selected by pressing theControl or Shift key.
⑤ Click the ‘Graph’ button.
The output from multiple result files can be displayed onto a single graph. To display asecond output, select a different graph result file in Step 1 above, and plot it in the samegraph area. The numerical labels shown in the legend below the graph (i.e., #1 and #2)
refer to the numbers written to the left of the file names in the window.

Graph result file numbers

制御信号

Loading and plotting large amounts of data are a slow process. When the number ofdata points exceeds the specified number, it is possible to omit some data points fromthe display (low-resolution mode), or to display all the data points (full-resolution mode).
Low-resolution graphs are denoted by an asterisk after the file number in the label
below the graph.

Asterisk (*) indicatesgraph is displayed in low
resolution mode

The default setting is to cull points if there are 10,000 or more. To switch between lowand full-resolution modes, select ‘Tools’ from the ‘File’ menu, or click the corresponding
toolbar button. The low-resolution mode is also described in Section 6.5.

- 95 -

(2) Graph display for the frequency-characteristic calculation
When a frequency-characteristic calculation result file is selected, the words‘frequency characteristic’ are appended to the file name and the graph is createdwith frequency on the horizontal axis. The absolute value and phase are displayedon the vertical axis by default. The horizontal axis has a logarithmic scale if that
option was chosen for frequency sampling. Modified graph displays are produced in
the same way as normal graph displays.

Indicates file is frequency
characteristic result file
Absolute value graphPhase angle graphLog-scale axis

- 96 -

(3) Modified graphing
Modified graphs involve the 5 following actions.

① Integration• displays the integrated result of the selected output.
② Fourier transform• displays the Fourier transform of the selected output. The phase angle is also
displayed when the ‘Phase angle display’ checkbox is checked.
③ Fourier-series expansion (specified interval)• performs a Fourier-series expansion over a specified range of the selected data. The
phase angle is also displayed when the ‘Phase angle display’ checkbox is checked.
The calculation range is set with the endpoint determined automatically from thespecified reference frequency once the starting point has been set (moved left or right).

- 97 -

④ Constants (a*f(t)+b)• multiplies the selected output by a specified constant a and adds a specified offset b.

⑤ XY plot• selects two signals and plots a graph by using one as the horizontal axis and theother as the vertical axis (for instance, this can be used to render the i-Φ characteristics
from the current and magnetic flux). Click the ‘Plot’ button to display the following
screen. Select the signals here in the same way as on the main XPLT screen, and set
them for use as the X and Y axes.

- 98 -

Only one signal may be selected for the X axis (once it is selected, the ‘X axis >’button will be deactivated). Multiple signals may be selected for the Y axis.

- 99 -

Click the OK button to display an XY plot as shown below.

- 100 -

(4) Panel button operations
Adds analysis-result files to the list.
Deletes the selected analysis-result filefrom the list.
Displays the added analysis-result
files. This is used to select the file tograph when multiple files have been
added. Only one file can be selected.

Adds one graph screen.
Deletes one graph screen.

Selects the item to be plotted.
Only one item can be selected.

Drag an item with the mouse to move theboundary line.

Selects the results to output. Hold down
the Shift or Control key on the keyboard
to select multiple results.

After selecting items, click this button tocreate the graph.
Click this button to display the result ofintegration or a Fourier transform of thedisplayed graph.

Check/uncheck to enable/disable grid line
display.

- 101 -

(5) Graph display area

Graph area

Plot area

A white graph background indicates the currently
selected data. A function can be plotted on thecurrent graph by selecting it and clicking the‘Graph’ button. To load the graph into a different
area, click the ‘Add graph’ button to create the newgraph area.

Check this checkbox to select the data if you
want to save it in CSV format or copy it to the
clipboard.

- 102 -

9.4

Graph editing

Select any waveform or the legend of the graph and right-click with the mouse todisplay a menu. The plot line then displayed with a thick line is the selected waveform.

Change color
The color of the selected curve can be changed. Select ‘Change color’ from the menu
to open the ‘Color settings’ dialog. Select the desired color and click ‘OK’. The curvechanges color accordingly.
Change thickness
You can change the line thickness of the selected curve. Select ‘Change thickness’
from the menu and select the desired thickness magnification.
Change Line Pattern
It is possible to change the line type of the plotted graph. Choose one line type (solidline, dash line, etc) from the menu options.
Change Marker
It is possible to add a marker to a waveform (the marker is set to ‘None’ by default).
Marker Size
You can set the marker size when adding markers to the waveform.
DeleteSelecting a curve in the graph by clicking on it gives it a thicker line width. Right-click
and select ‘Delete’ from the menu to delete the selected curve. The graph area still
remains even if all the curves have been deleted. To delete the graph area also, clickthe ‘Delete graph’ button in the panel on the right.
Clear Selections
This menu item deselects a selected curve, reverting its line width back to the normal.
Low-resolution display
This option switches the display of a curve from full to low resolution. This item cannot
be selected when the curve is already displayed in low-resolution display mode.
Full-resolution display
This option switches the display of a curve from low- to full-resolution. This item cannot
be selected when the curve is already displayed in full-resolution display mode.

- 103 -

Display numerical data
This option displays the numerical values for the selected curve in a text editor(Windows Notepad (notepad.exe) by default). The numerical data are displayed in tabseparated format, allowing copying and pasting to Excel or similar spreadsheet
software. You can change the choice of text editor. (Windows Notepad is slow whendisplaying a large volume of data, so using a faster text editor is recommended.)

Right-clicking away from a curve but still in the graph area displays a menu containing
only the ‘Display numerical data’ item. Selecting this item displays the numerical data
for all the curves in the graph.

- 104 -

Editing the properties list
Clicking the ‘Graph properties’ tab at the bottom of the screen’s left panel activates theproperties-list mode, which displays the properties list for the current graph.

Maximum and minimum values can be set for the X- and Y-axes in the properties list.
If different quantities (such as voltage and current) are plotted simultaneously on asingle graph, the properties list for all the corresponding Y-axes are also shown.
Clicking on the X- or Y-axis graph label while in properties-list mode allows a changeof the corresponding measurement units. It is also possible to change the units of theX- or Y-axis by clicking the legend of the X- or Y-axis, respectively.

Click the label to change units
Select the units- 105 -

9.5

Menus

(1) File menu

New
This option erases all the currently displayed graph data and displays a new graph.
Open template
A template is a group of files containing generic patterns of presentation that can beused as models for creating graphs of the same type. A template must be created fromindividual template files before it can be used. To open template files, select ‘Open
template’ from the ‘File’ menu in the main window. The following file-selection screen
appears. The arrow button is used to move the file selected on the left to the list of files
to be opened, on the right.
Lists the names of files that can beused in templates. A circle to the left ofa file name indicates the file exists.
Folder names can be checked byscrolling the display with the scroll bar.

When using all the files tocreate the graph, click thisbutton to move all the files tothe list on the right at once.

Moves only the selected fileto the list on the right.

Used to select files not registered as
templates. Displays new files in the list.

Save to template/Save as to template
After displaying the graphs, select one of these menu items to save the currently
displayed graph items.

- 106 -

Page settings
This option is used to specify the number of graphs printed per page (i.e., on one sheetof paper) and the page margins.

Print preview
A preview is shown of how the currently displayed graphs will appear when printed.

Print
The displayed graphs are printed. If any of the graphs have been checked, only thechecked graphs are printed.
Exit
The application terminates.
- 107 -

(2) Tools menu

Selection• enters the normal mode for selecting a waveform. Click this button to switch from the‘Enlarge waveform’ mode described below to the normal mode.
Enlarge waveform• enters the mode for enlarging a waveform. This mode causes the mouse cursor tochange to a magnifying glass. Drag any part of the graph to zoom in to that region.
Right-click to return to the normal selection mode.
Restore• restores an enlarged waveform display to the normal display.
Display time difference• displays two markers on the graph (red and blue). Use the mouse to drag the markers
to the waveforms you would like to focus on. The times and differences indicated by
the two markers are displayed in the upper left corner of the graph. Select [Delete
marker] to delete that marker.

- 108 -

Display waveform values
Two ordinate value markers are displayed, showing the corresponding values and theirdifference.

Change entire graph size
• changes the display size of the entire graph.

Reset all checkboxes• resets all checkbox settings for the graph selection states.
Redraw graph• reloads the data files of the displayed graph and redraws the graph. If the data in theanalysis result files (*.xpf files) have changed because a calculation was redone, thecurrently displayed graph contents can be replaced with the new analysis results.
Save in CSV format• saves the selected graph in CSV format. Selecting this item displays the file-saving
dialog, where the user can specify a filename. When saving multiple graphs, a CSV fileis created for each graph. The output for a graph saved in CSV format is shown on thenext page. Note that saving a low-resolution graph in csv format causes that data to beculled. In this case, “culled” will appear on the first line of that file, and “*” will beappended to the item name of the culled data.
- 109 -

Signal type

Analysis result file No.

Part nameLow-resolution display mode/Full-resolution display mode
• switch between the low- and full-resolution display modes. The graph display
toggles between these modes each time these items are selected. The current mode
is displayed on the toolbar.
Toolbar in low-resolution mode:

Toolbar in full-resolution mode:

Move up• Moves the currently active graph up one position.
Move down• Moves the currently active graph down one position.

- 110 -

(3) Graph menu

Save graph image – Save to file• saves the current graph as an image file such as a metafile or bitmap file.
Save graph image – Save to clipboard• copies the current graph to the clipboard in bitmap format or metafile format, allowing
it to be pasted into, e.g., Microsoft Word or Excel.

(4) Setup menu
Setup
• Opens the setup window, where it is possible to change the settings of XPLT.
<Numerical data output settings>

Program used for displaying numerical data
In this option it is possible to choose the program used for displaying numerical
data. By default, the program used for displaying numerical data is the notepad(notepad.exe), which is installed by default in Windows. However, when opening
large files in notepad it takes a long time to show its contents. Therefore, it isrecommended to use a lightweight text editor.
Case name display setting when outputting numerical data
In this option it is possible to choose to show the case name of the graph in the firstrow of the csv file, when outputting numerical data to a csv file. When the checkbox
is checked, the case name will be shown. When the checkbox is not checked, thecase name will not be shown (in this case, the first row will be the data label andthe data will be outputted from the second row)
- 111 -

<Graph settings 1>

Low-resolution display setting
In this option it is possible to specify the total number of points that triggers the
low-resolution display setting. By default, it is set to 10000 points.
Phase display setting of frequency characteristic calculation result
In this option it is possible to choose to display the phase information when plotting
a frequency characteristic waveform. If the checkbox is checked, the phase will be
displayed in the plot. If the checkbox is not checked, it will not be displayed.

(5) Help menu
About...
• Displays the XTAP version information- 112 -

(6) Toolbar

Switches the plotting mode

Replots the displayed graph
Clears all checkboxes
Changes the size of the entire graph
Erases markers.
Displays the waveform value difference(right axis) markers
Displays the waveform value difference(left axis) markers
Displays markers showing timedifference.
Resets the graph display area
Switches to enlarge waveform display
mode
Switches to selection mode
Opens a template.

- 113 -

10 Creating and Editing Macro Parts

XTAP allows the creation (registering) of multiple circuit parts or control-block parts
together as a single new part. Once a part is registered in this way, it can be reused asoften as needed. When reused, its parameter values can also be changed.

10.1 Packaging procedure (creating macro parts)
A created circuit can be ‘packaged’ to create a new part (a ‘macro part’).
1. Create a circuit diagram. Create appropriate terminals to connect the parts toeach other by selecting the terminals from the ‘00 Installation/terminals’ partcategory, and placing them in the diagram. In the example circuit diagram shown
below, a value calculated in the control system is passed to the electrical circuit
as a voltage source. The ‘01 Terminal (circuit)’ part can be used to connect theterminals of electrical-circuit parts (circled in red below) to other circuits. The
control-system terminals TIME1, PI, and ‘Frequency’ (circled in blue below) do
not need to be connected to other parts; hence, use the ‘05 Terminating output
terminal (control)’ part to prevent terminals from being automatically appended tothese parts when the circuit is packaged. If the circuit contains a terminal that is
not connected to an output terminal or terminating terminal, the corresponding
terminal is automatically appended to that element when the circuit is packaged.

Specifying part parameters with text strings enables them to be specified as macropart parameters once the circuit has been made into a macro part. In this example, aparameter is specified for the ‘Frequency’ terminal using the parameter name FREQ.
It should be noted that only alphanumeric characters (uppercase letters, lowercase
letters or numbers) and underscores “_” can be used for the parameter names.

- 114 -

The following example screen shot shows a variable named ‘Lval’ being specified forthe parameter of an inductor. It is important to note that when a variable is specified fora parameter, the auxiliary units of that parameter (i.e., unit prefixes such as M, k, m orμ) are ignored. The value of Lval can be set from the macro part’s properties as
described later, but for the present case, if Lval is set to 10.0E–3, the inductor value
used in calculations will be 10.0E–3 [H] and not 10.0E–3 [mH].

2. Select the circuit area to be packaged. In this example, ‘Select all’ is selected fromthe ‘Edit’ menu to select the entire circuit diagram. The entire circuit can also be
selected using the mouse.

3. Select ‘Package’ from the ‘Circuit’ menu.

This operation can also be performed by clicking the toolbar button indicated below.

- 115 -

4. The following screen appears, allowing the macro part to be registered in the partcategory window. Only the category ‘99 User's Components’ can be selected. A
subcategory can be selected only if it has already been created. See Section 10.6
for details of how to create and delete categories in the part-category window.
Select the part name with which the macro part is to be registered, then click ‘OK’.
In this example, the part name ‘Control SIN power source’ has been selected.

5. Specify the caption name that will be used to label the macro part on the canvas.
This may include upper- and lowercase letters, the underscore character (_), andnumbers. Caption names may not start with a number and cannot containJapanese characters or other Asian-width characters.

Click ‘OK’ to create the macro part on the canvas.

- 116 -

The original part type determines how the terminals of the created part are handled,
as shown below.
Terminal (circuit) parts become red square terminals.
Input terminal (control) parts become yellow squareterminals.

Output terminal (control) parts become blue
square terminals

Terminating terminal (circuit) parts andterminating output terminal (control) parts do
not extend outside the part.

6. The part created in the part-category window is registered.

- 117 -

If the part was created in a previously specified subcategory, it is registered in thatsubcategory.

7 Method for setting parameters
In Step 1, the parameter for the ‘Frequency’ part was entered using the text string
FREQ, making it a parameter for the macro part. We here describe how to specify
this parameter when using the macro part.
Composition of macro part (Sin_Wave1)

Double-click on the macro part ‘Sin_Wave1’ to open its ‘parameter setting’ screen.
Specify the value of the ‘Frequency’ parameter in Sin_Wave1 as 50.0, as shown
below. As explained above, if the original circuit part enabled the selection of
auxiliary units (prefixes for the unit of measurement such as M, k, m, etc.) prior
to packaging, those auxiliary units are ignored when the parameter value is set
in the macro part.

- 118 -

- 119 -10.2 Changing macro parts(1) Changing the circuits of macro parts placed in circuit diagrams
This section describes how to change the circuit within a macro part that is placed in acircuit diagram. Changes made to macro-part elements are applied to all the partscontained in the circuit diagram (or macroed circuit diagram) that were created fromthat part. Changes are applied even to a new part that is introduced into the circuit
diagram via the ‘part category’ window, provided that this change was made in thecircuit diagram. (In the circuit diagram, the same macro parts all have the same
configuration, and the configuration in the circuit diagram has priority). However, partconfigurations that are modified in the ‘part category’ window do not affect the original
part configuration; thus, a part placed on another circuit canvas will retain the original
configuration.
1.

Right-click the macro part you want to edit. The ‘macro part’ menu appears.
Select ‘Edit packaged diagram’.

2.

The circuit diagram that the macro part was packaged from is displayed. The
background color of the circuit-diagram canvas is gray, as when editing icons.

3.

Edit and save the circuit diagram.

- 120 -

(2) Changing circuits of macro parts registered in the ‘part category’window
The circuit of a macro part registered in the ‘part category’ window is edited as follows.
1.

Select ‘Open’ – ‘Open component’ from the ‘File’ menu, or click the toolbar
button used to open files and select ‘Open component’.

2.

Select the macro part you want to edit, then click ‘Display part’.

- 121 -

3.

The circuit diagram from which the macro part was packaged is displayed on acanvas with a blue background.

4.

Edit and save the circuit diagram.

- 122 -

10.3 Editing macro-part icons
The icon of a created macro part is edited as follows.
1.

Select ‘Open’ – ‘Open component’ from the ‘File’ menu, or click the toolbar
button used to open files and select ‘Open component’.

2.

Select the macro part you want to edit, then click ‘Display part’.

The button operations are described below.
Ok• opens the editing screen for the icon of the macro part.
Property• used to register parameters/formulas, or change part caption names.
Display part
• displays the parts that compose the macro part (the original circuit diagram). This isused to change the circuit configuration or part parameters.

- 123 -

3.

The icon-editing screen is displayed on a canvas with a blue background.

The following operations can be performed in the icon-editing screen:

Form (Z) menu (drawing objects)

Select• selects a drawing object placed on the component canvas.
Straight line
• creates a straight line.
Triangle• creates a triangle.
Rectangle• creates a rectangle.
Circle• creates a circle.
Text string• creates a text string.
- 124 -

Line
TriangRectangl

CircleText stringLine• creates a line.
1. Select ‘Line’ from the ‘Form’ menu.
2. Move the mouse cursor to the component canvas, and click the starting location.
3. Drag the mouse to draw the line to the desired end location.
4. Select ‘Select’ from the ‘Form’ menu.
5. Double-click the created line to display its properties screen. Set the required
property values to adjust the line features.

Pen information
Pen Width: sets the line thickness.
Pen Color: sets the line color.
Coordinate information
Start point: sets the coordinates of the starting location.
Endpoint: sets the coordinates of the end location.
ArrowsNone (default): leaves the line without arrow ends.
Start point: adds an arrow to the starting end of the line.
Endpoint: adds an arrow to the endpoint of the line.
Both: adds arrows to both ends of the line.

- 125 -

Triangle• creates a triangle.
1. Select ‘triangle’ from the ‘Form’ menu.
2. Move the mouse cursor to the component canvas, and click the location at whichto create the triangle. A triangle is displayed.
3. Select ‘Select’ from the ‘Form’ menu.
4. Double-click the created triangle to display its properties screen. Set therequired property values to adjust the triangle features.

Pen information
Pen Width: sets the line thickness.
Pen Color: sets the line color.
Fill information
Fill: check this box to fill the triangle with the selected color.
Fill color: sets the fill color.
Coordinate information• sets the triangle corner coordinates.

- 126 -

Rectangle• creates a rectangle.
1. Select ‘Rectangle’ from the ‘Form’ menu.
2. Move the mouse cursor to the component canvas, and left-click at the desired
location of the top-left corner of the rectangle.
3. Drag the mouse to define the size of the rectangle.
4. The rectangle is created when you stop dragging the mouse.
5. Select ‘Select’ from the ‘Form’ menu.
6. Double-click the created rectangle to display its properties screen. Set therequired property values to adjust the rectangle features.

Pen information
Pen Width: sets the line thickness.
Pen Color: sets the line color.
Fill information
Fill: check this box to fill the rectangle with the selected color.
Fill color: sets the fill color.
Coordinate information
Top-left coordinates: sets the coordinates of the top-left corner.
Width: sets the width.
Height: sets the height.
Rectangle shape
Rectangle: defines a normal rectangle (square corners).
Rounded rectangle: gives the rectangle rounded corners.

- 127 -

Circle• creates a circle.
1. Select ‘Circle’ from the ‘Form’ menu.
2. Move the mouse cursor to the component canvas, and left-click at the desired
location of the top-left of the circle frame.
3. Drag the mouse to define the size of the circle.
4. A circle is created when you stop dragging the mouse.
5. Select ‘Select’ from the ‘Form’ menu.
6. Double-click the created circle to display its properties screen. Set the required
property values to adjust the circle features.

Pen information
Pen Width: sets the line thickness.
Pen Color: sets the line color.
Fill information
Fill: check this box to fill the circle with the selected color.
Fill color: sets the fill color.
Coordinate information
Top-left coordinates: sets the coordinates of the top-left corner of the circle frame.
Width: sets the width of the circle frame.
Height: sets the height of the circle frame.
Customize circle
Make into arc: turns the circle into an arc when this box is checked.
Start angle: sets the starting angle of the arc.
Sweep angle: sets the sweep angle of the arc.

- 128 -Text string• creates a text string.
1. Select ‘Text string’ from the ‘Form’ menu.
2. Move the mouse cursor to the component canvas, and click at the desired
location of the text string.
3. The cursor appears for entering text.
4. Enter the desired text string.
5. Select ‘Select’ from the ‘Form’ menu.
6. Select the created text string and right-click to display a menu. Select ‘Properties’
from this menu to display the properties screen for the text string. Set therequired property values to adjust the text-string features.

Current font
Click ‘Set’ to set the font.

Coordinate information• specifies the coordinates of the center of the text string.
Display orientation
Normal: displays the text string normally.
Right 90°: rotates the text string clockwise so that its left side is at the top.
Left 90°: rotates the text string counterclockwise so that its left side is at the bottom.
Caption• specifies the content of the text string.

- 129 -

10.4 Connection-terminal settings
This section describes the screen for defining the settings of the part terminals.
Terminals can be placed on the component canvas in the same way as when editing
icons. Two parts are shown as examples in the screens below..

2

1

1.
2.
3.

3

Terminals (default color: red) of an electrical-circuit part are used to connect one
electrical-circuit part to another.
Input terminals (default color: orange) of a control-system block part connect an
input signal to the part.
Output terminals (default color: blue) of a control-system block part connect toan output signal produced within the part.

- 130 -

Form menu (terminals)

Terminal• creates a terminal for an electrical-circuit part.
Input terminal• creates an input terminal for a control-system block part.
Output terminal• creates an output terminal for a control-system block part.
Multiple-signal input terminal• creates a control system block part input terminal for handling vector signals
Multiple-signal output terminal• creates a control system block part output terminal for handling vector signals- 131 -

Terminal properties screen
Double-click on a terminal or right-click on it and select ‘Properties’ from the menu thatappears, to display the terminal’s properties screen.

Terminal information
Type: displays the terminal type (terminal, input terminal, output terminal).
Terminal color: used to select the color of the terminal.
Display orientation• selects the orientation of the terminal (horizontal or vertical).
Coordinate information• specifies the coordinates of the terminal’s center. This must be entered in multiplesof 4 (i.e., 0, 4, 8, etc.) since terminals are always placed on grid lines.
Name• specifies the name used to manage the connection line (e.g., electric-circuit wire orcontrol-system wire) connected to the terminal.
Terminal number• specifies the output sequence of the terminal information output to *.xtf files (XTAP
Text Files). Terminals numbers must be unique in parts.

- 132 -

10.5 Registering parameters/formulas
Parameters and formulas can be registered in created macro parts. Once registered,a parameter or formula is entered when the macro part is set in the circuit diagram.
1.

Select ‘Open’ – ‘Open component’ from the ‘File’ menu, or click the toolbar
button used to open files and select ‘Open component’.

2.

Select the macro part you want to edit, then click ‘Properties’.

3.

The part’s properties editing screen appears.

- 133 -

- 134 -4.

To register a parameter, select ‘SubParams’ under ‘Tag ID’ and enter theparameter value next to ‘Value’ under ‘Initial value’. This is demonstrated below for
the parameter ‘b = 100’.

5.

To register a formula, select ‘SubExpression’ under ‘Tag ID’ and enter the formula
next to ‘Value’ under ‘Initial value’. This is shown below for the formula ‘a = 5 * b’.

- 135 -

6.

Click ‘Ok’ to close the properties screen. Click ‘Ok’ in the ‘Open component’screen to close the component.

7.

When the macro part is placed in the circuit diagram and its properties are
viewed, the registered parameter and formula are entered.

- 136 -

10.6 Part-category window composition; creating/deleting
categories
Categories can be created within the ‘99 User's Components’ category in the ‘part
category’ window. Categories created within the ‘99 User's Components’ category orparts registered there can also be deleted.

(1) Creating subcategories
This section describes how to create categories in the part-category window. All usercreated categories are created as subcategories within the ‘99 User's Components’category.
1.

Select ‘Create category’ from the ‘File’ menu.

- 137 -

2.

The ‘category input’ screen appears. Enter the desired category name in the‘Category name’ field. To create another category within this category, specify
the higher-level category name, followed by the lower-level category name, with
the names separated by ‘¥’. The screen shot below shows the category ‘User1’
being created.

(2) Deleting categories/macro parts
To delete a created category, right-click on its name and select ‘Delete’ from the rightclick menu. If any parts have been registered in a category, they must all first be deleted
before the category itself can be deleted. Parts are deleted by the same method as theone used for categories.

- 138 -

11 Other

11.1 Starting XTLC (line constants calculation program)To start XTLC from XTAP, select ‘XTLC (line constants calculation program)’ from the‘Tools’ menu in the main window.

The same operation can also be performed by clicking the toolbar button indicatedbelow.

Appendix 1 describes how to use XTLC.

11.2 Starting XFIT (system identification program)To start XFIT from XTAP, select ‘XFIT (system identification program)’ from the ‘Tools’
menu in the main window.

The same operation can also be performed by clicking the toolbar button indicatedbelow.

Appendix 2 describes how to use XFIT.

- 139 -

- 140 -XTLC (Line Constants Calculation Program)
Version 2.4

Instruction ManualCentral Research Institute of Electric Power Industry (CRIEPI)
December 2022

- 141 -

- 142 -Contents

1

Introduction ................................................................................................................ 145
1.1 ....... Overview ............................................................................................................ 145
1.2 ....... Main window ....................................................................................................... 146
1.3 ....... Menu bar and toolbar ......................................................................................... 146

2

Creating New Line-Placement Data .......................................................................... 149
2.1 ....... Selecting the line type ........................................................................................ 149
2.2 ....... Entering line-placement data .............................................................................. 149
2.3 ....... Line-constant calculation .................................................................................... 155
2.4 ....... Displaying line-constant calculation results ........................................................ 156

3

Referencing Existing Line-Placement Data ............................................................... 162
3.1 ....... Referencing line placement data ........................................................................ 162
3.2 ....... Revising line-type information ............................................................................ 162
3.3 ....... Calculating line constants and displaying results ............................................... 162

4

Using Line Model Data Created in XTLC ................................................................... 163
4.1 ....... How to specify the data for the distributed-parameter line model ....................... 163
4.2 ....... How to specify the data for matching resistance ................................................ 167

5

Registering Information in Line/Cable Databases...................................................... 171
5.1 ....... Databases .......................................................................................................... 171
5.2 ....... Overhead transmission lines .............................................................................. 172
5.3 ....... Overhead distribution lines ................................................................................. 173
5.4 ....... Cables ................................................................................................................ 173
5.5 ....... Line/cable database functions ............................................................................ 174- 143 -

- 144 -1 Introduction
1.1 Overview
The line-constants calculation program (XTLC) calculates the line constants
referenced by the XTAP distributed-constant line model, by placing line conductors
and using physical constants. It can also be used independently and specifically forline-constant calculations. Figure 1 outlines the basic operation. Further details of how
to use each function are provided in the sections indicated.
⚪ Line-constants calculation [XTLC]Creating new data: see Section 2.
Using existing data: see Section 3.
Line-type selection

Overhead line
(transmission line)

Underground cableSee Section 5
Repeated for every lineLine
placement

Overhead line
(distribution line)

Select line/cable type

No corresponding
line type

Register in line/cabledatabase

Register line
placement data

Specify line position
Line placement
data (*.lin)

Calculate line constant

Register constants data for line model⚪ Use of constants data for distributed-constant line model [XTAP]Line model
constants data(*.xmf)

Reference line model
constants data

Use as constants for distributed-constantline model

See Section 4

Figure 1. Basic XTLC operation workflow● Line-placement data are contained in files used for calculating constants. They include
physical information for each line, such as overhead-line pole information and buried
cable locations.
● Line model constant data contain saved line-constant information calculated by XTLC.
They can be referenced by XTAP distributed-constant line parts.

- 145 -

1.2 Main window
The main window, that appears when XTLC is started, is the following.
Menu bar

ToolbarLine placement data area

Status bar

It consists of a menu bar, toolbar, and status bar, and an area for displaying lineplacement data.

1.3 Menu bar and toolbar
The XTLC menu bar is described below.
File (F) menu

- 146 -

New
● creates a new line-placement data file. The same operation can also be performedby clicking the toolbar button shown below.

Open● loads an existing line-placement data file and opens it in the line-placement data
input screen. The same operation can also be performed by clicking the toolbar
button shown below.

Close● closes the line-placement data input screen.
Save● saves the line-placement data (replacing the old data with a newer version). The
same operation can also be performed by clicking the toolbar button shown below.

Save as● saves the line-placement data under a new user-defined name if required.
Exit● terminates XTLC.

- 147 -

View (V) menu
● enables or disables the display of the toolbar or status bar.

Databases menu
● opens the line/cable databases, letting the user search and edit line types alreadyregistered in the databases, and register new lines. See Section 5 for details of how
to register a new line type.

Overhead transmission line
● opens the overhead-transmission-line database.

Overhead distribution line
● opens the overhead-distribution-line database.

Cable● opens the cable database.

Help (H) menu

Instruction manual● gives access to this manual.

- 148 -

2 Creating New Line-Placement Data
2.1 Selecting the line type
Select ‘New’ from the ‘File’ menu in the menu bar, or click theThe ‘line-type selection’ dialog appears.

toolbar button.

Select the type of line-placement data to create, then click the ‘Select’ button.

2.2 Entering line-placement data
The line-placement data input screen is divided into areas for inputting lineplacement data and displaying them diagrammatically. The items specified in the
input area differ for overhead lines and underground cables.

Line placement data input area

Line placement diagram display area

The input area is used to enter line-placement data and the ground resistivity. The
data are entered in the following steps:①

Select the type.
Select either ‘Erase’ or ‘Do not erase’. (Select ‘Erase’ if it is assumed that thefull line is at zero potential. This item is not available in the case of anunderground cable.)- 149 -

②

Conductor No. (input not required)③

The conductor number is automatically assigned when the line type is specified(Item 3 below). (0 when selecting ‘Erase’ in the type selection.)
Specify the line type.
Double-click the ‘Line type’ item to specify a line type. The Line/cable database
screen appears. Select the desired line or cable.

If the desired line or cable does not exist, save the data and close the lineplacement screen. See Section 5 for details of how to register the desired line
or cable in a line/cable database. After registering this line or cable, load thesaved data and continue the procedure. (See Section 3 for details of how toload existing data.)④

Enter the line placement.
● Overhead line
Specify the conductor placement by entering the pole information in the lineplacement data. A distribution line does not involve poles or conductor-interval
settings.

Add automatically- 150 -

Enter

To check conductor placement, click the ‘↓ Draw (check)’ button to draw theconductor placement in the line-placement diagram, as shown below.

● Underground cableSpecify the conductor placement by entering the buried cable positions andconduit-line information in the line-placement data.

Enter
Add automatically- 151 -

To check conductor placement, click the ‘↓ Draw (check)’ button to draw theconductor placement in the line-placement diagram, as shown below.

⑤

Specifying a Twist group
For a ‘Twist group’ (overhead line) or ‘Triplex group’ (underground cable),
specify three lines or cables as a group by selecting the same group number
for them.

Example: Setting conductors 1 to 3 as Group 1, and 4 to 6 as Group 2.

Group 1
Group 2For a non-twist line, input a 0 under ‘Twist group’ or ‘Triplex group’.
Since in the case of underground cables, the assumption is that each cable will be
installed along the conduit lines, it is not possible to rigorously simulate situations
where triplex cables are installed in a group along a single conduit line. When triplex
cables are placed as underground cables, place three cables based on theassumption that all three phases of the triplex cable can be fit into the conduit line.
Place in such a way that the three cables are attached in an equilateral triangle.
⑥

Save the line-placement data.
Select ‘Save’ from the ‘File’ menu on the menu bar, click the
toolbar button,
or click the ‘Save’ button to save the data. To apply the updated information to
the calculation, data must be saved before performing the line-constantcalculation.
The following operations can be performed in the line-placement data input
screen:- 152 -

Selection
Click the first cell in a row to select that row.

Click

The row is then selected.

Selected

Multiple selection (continuous range)
Hold down the Shift key on the keyboard and click the first cells of the first and lastrows in the desired range.
First row

Last row

All the rows in that range will then be selected.

Selected

Multiple selection (separate rows)
Hold down the ‘Ctrl’ key on the keyboard and click the first cells of each requiredrow.

- 153 -

Only these rows will then be selected.

InsertingSelect the location at which to insert a new row. Press the ‘Insert’ key on the
keyboard to insert a new row immediately above this location.

New row is inserted

Inserting a selected (copied) row
Select the location at which to insert a new row. Press the ‘Alt’ and ‘Insert’ keys on
the keyboard together to insert a new row immediately above this location. The newrow has the same content as the row previously at this location. Conductor numbers
are automatically changed.

Copied row is inserted

DeleteSelect one or more rows and press the ‘Delete’ key on the keyboard to delete them.

Conductor numbers are automatically changed.

MovingA single selected row can be moved up or down. Select the row and press ‘Alt’ andthe ‘up arrow’ cursor key on the keyboard together to move the row upward. Similarly,
use the ‘down arrow’ cursor key to move the row downward. Conductor numbers
are automatically changed to handle the move.
- 154 -

2.3 Line-constant calculation
Click the ‘Calculate’ button to perform the line-constant calculation. After creating or
updating line placement data, the data must be saved before proceeding to the lineconstant calculation.

The ‘calculation-type selection’ dialog appears. Select the type of calculation to
perform. If twist or triplex are specified, the ‘Create fixed-constant line model’ and‘Create frequency-dependent line model’ items cannot be selected*.
*For transmission lines with a three-phase twist, it is possible to simulate a fixed-parameter line
constant line model by using ‘Three-phase twist line model (fixed-parameter)’ in the XTAP
distributed-constant line parts.

Different parameters are required for each of the selected calculation types. For
example, when the frequency-dependent line model has been selected, the following
screen appears. Enter the required parameters, then click ‘Run’ to start the lineconstant calculation.
Select unit:
● Hz
● kHz
● MHz
Select unit:●m● km

If either of the following items is selected, a ‘file selection’ dialog appears when thecalculation finishes. The file selected in the dialog is then used to save the line-model
data for use by XTAP.
● Create π-type equivalent circuit model● Create fixed-constant line model● Create frequency-dependent line model●Matching resistanceEnter a file name, then click ‘Save’.

- 155 -

2.4 Displaying line-constant calculation results
Line-constant calculation results are displayed in the ‘Line-constant calculation results’or ‘Plot dialog’ screen. One of these screens appears when the line-constantcalculation ends.
①
Line-constant calculation results
This displays the line-constant calculation results. If ‘Constant calculation only’ or‘Create frequency-dependent line model’ was selected in Section 2.3, the ‘Plot
dialog’ described below in Item 2 is displayed first, and then the ‘Line-constantcalculation results’ screen appears when this dialog is closed.

If ‘Constant calculation only’ or multiple ‘Specified frequency’ values werepreviously specified, only the result calculated first is displayed. To display all thefrequency results, check the *.mat file located in the same folder as the result file.
They can then be checked using MATLAB. To save the calculation results, select‘Save’ from the ‘File’ menu. Alternatively, select ‘Copy all’ from the ‘Edit’ menu tosave the results by pasting them into external software.

Table 1 shows the line constant list displayed in the ‘Line constant results’. Referto the following documentation for details regarding each constant.
[1] Central Research Institute of Electric Power Industry (CRIEPI) Research
Report H04014, “Development of a Line Constants Calculation Program for
Overhead Transmission Lines - An eigenvector normalization algorithm andan approximate formula for ground-return impedance –” (can be downloaded
from CRIEPI’s Web site)- 156 -

Table 1

Line constant list-----------------------------------------------------------------------Frequency = 5.00000E+001 [Hz]Phase domain constant (before GW elimination)-----------------------------------------------------------------------PHASE DOMAIN QUANTITIES (before ground-wire elimination)
Space inductance Ls in phase coordinates [H/m]1.15332E-006 2.86656E-007 1.63786E-007
2.86656E-007 1.15332E-006 2.86656E-007
1.63786E-007 2.86656E-007 1.15332E-006
3.72004E-007 3.03782E-007 1.95357E-007
1.95357E-007 3.03782E-007 3.72004E-007

3.72004E-007
3.03782E-007
1.95357E-007
1.81650E-006
2.58400E-007

Ground-return impedance Ze (including Ls) in phase
Real part:4.71730E-005 4.71656E-005 4.71435E-005 4.68207E-005
4.71656E-005 4.71730E-005 4.71656E-005 4.68167E-005
4.71435E-005 4.71656E-005 4.71730E-005 4.67989E-005
4.68207E-005 4.68167E-005 4.67989E-005 4.64762E-005
4.67989E-005 4.68167E-005 4.68207E-005 4.64600E-005
Imaginary part:5.61990E-004 2.87882E-004 2.44337E-004 3.06716E-004
2.87882E-004 5.61990E-004 2.87882E-004 2.84512E-004
2.44337E-004 2.87882E-004 5.61990E-004 2.47195E-004
3.06716E-004 2.84512E-004 2.47195E-004 7.52239E-004
2.47195E-004 2.84512E-004 3.06716E-004 2.60287E-004

1.95357E-007
3.03782E-007
3.72004E-007
2.58400E-007
1.81650E-006

Space inductance

Modal domain constant(before transformation matrix normalization)-----------------------------------------------------------------------MODAL DOMAIN QUANTITIES (before eigenvector rotation)Line series impedance

4.67989E-005
4.68167E-005
4.68207E-005
4.64600E-005
4.64762E-005

2.47195E-004
2.84512E-004
3.06716E-004
2.60287E-004
7.52239E-004

Shunt admittance y in modal coordinates [S/m]Real part:-6.45612E-012 -5.66088E-025 -1.93744E-011
Imaginary part:2.50197E-009 3.60544E-009 4.21510E-009

Line parallel admittance

Propagation constants gamma in modal coordinates [1/m]Real part:1.82258E-007 6.49314E-008 7.08599E-008
Imaginary part:1.30484E-006 1.06650E-006 1.05462E-006

Propagation constant

2.93027E-004

Conductor internal impedance

Total series impedance Z in phase coordinates [ohm/m]
Real part:
8.24491E-005 4.71656E-005 4.71435E-005 4.68207E-005
4.71656E-005 8.24491E-005 4.71656E-005 4.68167E-005
4.71435E-005 4.71656E-005 8.24491E-005 4.67989E-005
4.68207E-005 4.68167E-005 4.67989E-005 3.39503E-004
4.67989E-005 4.68167E-005 4.68207E-005 4.64600E-005
Imaginary part:5.63927E-004 2.87882E-004 2.44337E-004 3.06716E-004
2.87882E-004 5.63927E-004 2.87882E-004 2.84512E-004
2.44337E-004 2.87882E-004 5.63927E-004 2.47195E-004
3.06716E-004 2.84512E-004 2.47195E-004 7.58026E-004
2.47195E-004 2.84512E-004 3.06716E-004 2.60287E-004

Characteristic impedance

Series impedance z in modal coordinates [ohm/m]
Real part:1.91824E-004 3.84136E-005 3.66652E-005
Imaginary part:
6.66733E-004 3.14302E-004 2.62509E-004

Ground-return impedance

Conductor internal impedance Zc in phase coordinates [ohm/m]
Real part:3.52761E-005 3.52761E-005 3.52761E-005 2.93027E-004
Imaginary part:
1.93711E-006 1.93711E-006 1.93711E-006 5.78691E-006

Characteristic impedance Z0 in phase coordinates [ohm]Real part:3.56699E+002 9.46781E+001 6.08974E+001
9.46781E+001 3.54126E+002 9.46781E+001
6.08974E+001 9.46781E+001 3.56699E+002
Imaginary part:-3.58050E+001 -1.88627E+001 -1.77957E+001-1.88627E+001 -3.60287E+001 -1.88627E+001-1.77957E+001 -1.88627E+001 -3.58050E+001

5.78691E-006

Propagation velocities in modal coordinates [m/s]
2.40765E+008 2.94571E+008 2.97887E+008

Propagation speed

Characteristic impedance z0 in modal coordinates [ohm]Real part:5.21332E+002 2.95802E+002 2.50119E+002
Imaginary part:-7.41909E+001 -1.80093E+001 -1.79606E+001

4.67989E-005
4.68167E-005
4.68207E-005
4.64600E-005
3.39503E-004

Characteristic impedanceLine series impedance
2.47195E-004
2.84512E-004
3.06716E-004
2.60287E-004
7.58026E-004

Voltage transformation matrix Tv (v_phase = Tv*v_mode)
Real part:5.79195E-001 -7.07107E-001 -3.68007E-001
5.73639E-001 -7.46545E-015 8.53889E-001
5.79195E-001 7.07107E-001 -3.68007E-001
Imaginary part:-1.94289E-016 -1.11022E-016 -2.82716E-003
2.47400E-003 -3.62296E-017 0.00000E+000
0.00000E+000 0.00000E+000 -2.82716E-003

Voltage transformation matrix

Space capacitance Cs in phase coordinates [F/m]1.08700E-011 -1.96320E-012 -6.06465E-013 -1.76637E-012 -4.65239E-013-1.96320E-012 1.12047E-011 -1.96320E-012 -1.10364E-012 -1.10364E-012-6.06465E-013 -1.96320E-012 1.08700E-011 -4.65239E-013 -1.76637E-012-1.76637E-012 -1.10364E-012 -4.65239E-013 6.79219E-012 -4.96389E-013-4.65239E-013 -1.10364E-012 -1.76637E-012 -4.96389E-013 6.79219E-012

Space capacitance

Current transformation matrix Ti (i_phase = Ti*i_mode)
Real part:6.05018E-001 -7.07107E-001 -4.06454E-001
5.21512E-001 -5.02228E-015 8.20769E-001
6.05018E-001 7.07107E-001 -4.06454E-001
Imaginary part:-2.17105E-003 -4.80084E-016 -2.94431E-004
2.13498E-003 8.63732E-016 -2.94526E-003-2.17105E-003 -5.91107E-016 -2.94431E-004

Current transformation matrix

Shunt admittance in phase coordinates [S/m]Real part:
0.00000E+000 0.00000E+000 0.00000E+000 0.00000E+000 0.00000E+000
0.00000E+000 0.00000E+000 0.00000E+000 0.00000E+000 0.00000E+000
0.00000E+000 0.00000E+000 0.00000E+000 0.00000E+000 0.00000E+000
0.00000E+000 0.00000E+000 0.00000E+000 0.00000E+000 0.00000E+000
0.00000E+000 0.00000E+000 0.00000E+000 0.00000E+000 0.00000E+000
Imaginary part:3.41492E-009 -6.16757E-010 -1.90527E-010 -5.54921E-010 -1.46159E-010-6.16757E-010 3.52006E-009 -6.16757E-010 -3.46718E-010 -3.46718E-010-1.90527E-010 -6.16757E-010 3.41492E-009 -1.46159E-010 -5.54921E-010-5.54921E-010 -3.46718E-010 -1.46159E-010 2.13383E-009 -1.55945E-010-1.46159E-010 -3.46718E-010 -5.54921E-010 -1.55945E-010 2.13383E-009

Modal domain constant(after transformation matrix normalization)------------------------------------------------------------------------

Line parallel admittance

MODAL DOMAIN QUANTITIES (after eigenvector rotation)
Series impedance z1 in modal coordinates [ohm/m]
Real part:
1.90103E-004 3.84136E-005 3.54574E-005
Imaginary part:6.67223E-004 3.14302E-004 2.62672E-004

Line series impedancePhase domain constant (after GW elimination)-----------------------------------------------------------------------PHASE DOMAIN QUANTITIES (after ground-wire elimination)
Total series impedance Z in phase coordinates [ohm/m]
Real part:
8.79763E-005 5.18901E-005 4.95627E-005
5.18901E-005 8.79618E-005 5.18901E-005
4.95627E-005 5.18901E-005 8.79763E-005
Imaginary part:
4.16443E-004 1.39217E-004 1.02141E-004
1.39217E-004 4.11339E-004 1.39217E-004
1.02141E-004 1.39217E-004 4.16443E-004
Shunt capacitance C in phase coordinates [F/m]1.08700E-011 -1.96320E-012 -6.06465E-013-1.96320E-012 1.12047E-011 -1.96320E-012-6.06465E-013 -1.96320E-012 1.08700E-011
Shunt admittance Y in phase coordinates [S/m]Real part:
0.00000E+000 0.00000E+000 0.00000E+000
0.00000E+000 0.00000E+000 0.00000E+000
0.00000E+000 0.00000E+000 0.00000E+000
Imaginary part:3.41492E-009 -6.16757E-010 -1.90527E-010-6.16757E-010 3.52006E-009 -6.16757E-010-1.90527E-010 -6.16757E-010 3.41492E-009

Shunt admittance y1 in modal coordinates [S/m]Real part:
0.00000E+000 0.00000E+000 0.00000E+000
Imaginary part:2.50200E-009 3.60544E-009 4.21517E-009

Line parallel admittanceLine series impedanceLine parallel capacitance

Characteristic impedance z01 in modal coordinates [ohm]Real part:5.21519E+002 2.95802E+002 2.50197E+002
Imaginary part:-7.28452E+001 -1.80093E+001 -1.68105E+001

Characteristic impedance

Voltage transformation matrix Tv1 (v_phase = Tv1*v_mode)
5.79194E-001 -7.07107E-001 -3.68012E-001
5.73641E-001 -7.46545E-015 8.53887E-001
5.79194E-001 7.07107E-001 -3.68012E-001

Voltage transformation matrix

Current transformation matrix Ti1 (i_phase = Ti1*i_mode)
6.05016E-001 -7.07107E-001 -4.06450E-001
5.21505E-001 -5.05808E-015 8.20768E-001
6.05016E-001 7.07107E-001 -4.06450E-001

Current transformation matrix

Line parallel admittanceImaginary part of Tv1 which will be discarded-7.47278E-004 -3.25177E-017 -1.98140E-003
1.73388E-003 -3.62296E-017 -1.96240E-003-7.47278E-004 -7.85046E-017 -1.98140E-003

Imaginary part of voltage transformation matrix
Symmetrical components(only displayed in case of three-phase line)-----------------------------------------------------------------------Propagation constants Gamma in phase coordinates [1/m]Real part:1.07247E-007 3.33391E-008 4.23153E-008
3.85996E-008 1.03556E-007 3.85996E-008
4.23153E-008 3.33391E-008 1.07247E-007
Imaginary part:
1.14810E-006 7.57169E-008 8.16053E-008
8.68693E-008 1.12976E-006 8.68693E-008
8.16053E-008 7.57169E-008 1.14810E-006

SYMMETRICAL COMPONENTS

Propagation constant

Positive-Sequence Impedance [ohm/km]
Real part:
3.69E-02
Imaginary part:
2.88E-01

Positive-sequence-phase impedanceZero-Sequence Impedance [ohm/km]
Real part:
1.90E-01
Imaginary part:
6.68E-01

Zero-sequence-phase impedance------------------------------------------------------------------------- 157 -

If the results screen is closed without saving, a ‘save confirmation’ dialog appears.
Click ‘Yes’ to save the results.

②

Plot dialog

The ‘Plot dialog’ appears if ‘Constant calculation only’ or ‘Create frequencydependent line model’ was selected in Section 2.3.
a. ResView1
This is displayed when the item below is selected as the calculation type, but notwhen only one frequency has been specified.
● Constant calculation only

Each ‘Plot’ buttons displays the corresponding plot.

- 158 -

⚪ Damping constant and propagation-velocity frequency response⚪ Characteristic-impedance frequency response⚪ Voltage transformation matrix frequency response- 159 -

b. ResView2
This is displayed when the following item is selected as the calculation type.
● Create frequency-dependent line modelThis dialog allows checking of the model precision by comparing the frequency
characteristics of the calculated line constant and of a frequency-dependent
model created by fitting it.

Each ‘Plot’ buttons displays the corresponding plot.
⚪ Characteristic admittance matrix [Y0] fitting results
The graphs for the specified row or column are displayed.

- 160 -

⚪ Characteristic admittance matrix [Y0] eigenvalue frequency characteristics(stability evaluation)⚪ Propagation function matrix [H] fitting results
The graphs for the specified row or column are displayed.

- 161 -

3 Referencing Existing Line-Placement Data
3.1 Referencing line placement data
Select ‘Open’ from the ‘File’ menu on the menu bar, or click the
toolbar button.
The ‘file selection’ dialog appears. Select a line-placement data file (*.lin file).

3.2 Revising line-type information
To revise a line type, double-click on the line type.
Double-click

The ‘line/cable database’ screen appears. Select the desired line type.

If the desired line type does not exist, save the data and close the line-placement
screen. Register the line type in the line/cable database (see Section 5), then load
the saved data and continue the procedure.

3.3 Calculating line constants and displaying results
See Sections 2.3 and 2.4.

- 162 -

4 Using Line Model Data Created in XTLC
4.1 How to specify the data for the distributed-parameter line
model
The following distributed-line constant parts can be used for created line-modeldata:● 01 π-type equivalent-circuit line model (XTLC)● 03 Fixed-parameter distributed-constant line model (XTLC)● 04 Frequency-dependent distributed-constant line model

Click ‘Browse’ in the ‘parameter setting’ screen to select line-model data. It is also
necessary to specify the number of phases (number of conductors) for the selectedline model data along with the line length. (It is not necessary to specify the line
length in the case of a distributed constant line model that is dependent on
frequency).

If the following message appears when clicking ‘Browse’, select ‘Save as’ from the‘File’ menu on the menu bar to save the circuit diagram.

An example is shown below.

- 163 -

● Overhead line example
When a conductor placement in XTLC as shown in the figure on the left below is
specified and then calculations are executed by selecting the π type equivalentcircuit model ,line model data is created as shown in the figure on the right below.

This example has three conductors and three phases. Therefore, specify ‘3’ as thenumber of phases in the parameter setting screen. Select the line-model data above
as the data file.

The number of part terminals in the circuit diagram is then updated to 3. The terminal
sequence is the conductor number sequence specified in XTLC.

- 164 -

Conductor No. 1
Conductor No. 2
Conductor No. 3● Cable example
When a conductor placement in XTLC as shown in the figure on the left below is
specified and calculations are executed by selecting the fixed-constant line model,line model data is created as shown in the figure on the right below.

This example has three conductors and three phases, with each phase consistingof a core-and-sheath combination. Therefore, specify ‘6’ as the number of phasesin the parameter setting screen. Select the above line-model data as the data file.

- 165 -

The number of part terminals in the circuit diagram is then updated to 6. The terminal
sequence is the conductor number sequence specified in XTLC. For each conductor,
the core is set first, then the sheath.

Conductor No. 1 coreConductor No. 1 sheath
Conductor No. 2 coreConductor No. 2 sheath
Conductor No. 3 coreConductor No. 3 sheath- 166 -

4.2 How to specify the data for matching resistanceThe created model data of the matching resistance can be used by using thefollowing component.
● 07 Matching Resistance
You can set the model data file to this component by selecting “Choose file”, in theparameter screen. Note that it is necessary to choose the number of phases usedin the selected model data.
When the following screen appears when you click on “Choose file”, it is necessary
to save the circuit schematic file by clicking on File > Save as, in the menu bar.

● Example using an overhead line
Specify the line position parameters in XTLC, like the figure below, then click on the
button “Calculate”. Finally, choose “Matching Resistance” in the window that appearson the screen. After the calculation ends, the data about the matching resistancematrix will be displayed on the screen, like the figure below.

- 167 -

Go back to XTAP and place the component “07 Matching Resistance” on the circuit
schematic file and save it. In this example a 3-phase 3-conductors line is considered,
therefore the parameter “Number of phases” of the XTAP component “07 Matching
Resistance” is set to “3”. Moreover, the data file calculated by XTLC is chosen in the“Data file” parameter.

After you set these values and close the properties screen of the component, thenumber of terminals on each side of the component will be updated to be three.
Moreover, the order of the terminals is the same order as specified in XTLC.

Conductor No. 1
Conductor No. 2
Conductor No. 3● Example using an underground cableSpecify the cable position parameters in XTLC, like the figure below, then click on the
button “Calculate”. Finally, choose “Matching Resistance” in the window that appearson the screen. After the calculation ends, the data about the matching resistancematrix will be displayed on the screen, like the figure below.

- 168 -

Go back to XTAP and place the component “07 Matching Resistance” on the circuit
schematic file and save it. In this example a 3-phase 3-conductors line is considered,however for each cable its core and its sheath are considered separately. Therefore,
it is necessary to set the parameter “Number of phases” of the XTAP component “07
Matching Resistance” to “6”. Moreover, the data file calculated by XTLC is chosen in
the “Data file” parameter.

After you set these values and close the properties screen of the component, thenumber of terminals on each side of the component will be updated to be six. Moreover,
the order of the terminals is the same order as specified in XTLC. However, for eachcable its core and its sheath are considered as different phases- 169 -

Conductor No. 1 coreConductor No. 1 sheath
Conductor No. 2 coreConductor No. 2 sheath
Conductor No. 3 coreConductor No. 3 sheath- 170 -

5 Registering Information in Line/Cable Databases
This section describes how to register information in line/cable databases. Before
registering information, close the line-placement screen if it is open.

5.1 Databases
There are six line/cable databases:⚪ Developer-provided databases● Overhead transmission lines: Overhead transmission lines.cbl● Overhead distribution lines: Overhead distribution lines.cbl● Underground cables: Underground cables.cbl⚪ Databases for users● Overhead transmission lines: Overhead transmission lines (for users).cbl● Overhead distribution lines: Overhead distribution lines (for users).cbl● Underground cables: Underground cables (for users).cbl
Searches are the only operation that can be done on developer-provided databases.
These databases cannot be updated by adding or deleting information. Databases
for users can have new or edited information registered in them. You can edit
developer-provided information by searching for the required information and thenperforming the ‘New’ operation to rename it and register it in a database for users.

Search, edit,
register, delete

SearchNew
User-use

Developerprovided

database

database

For users

Developer-provided

The search function and track-bar slider function enable simultaneous access todeveloper-provided and databases for users, enabling seamless use of thedatabases by the user.

- 171 -

5.2 Overhead transmission lines
Select ‘Overhead transmission line’ from the ‘Databases’ menu on the menu bar.

The ‘overhead-transmission-line database editing’ dialog then appears.

Different operations can be performed on the database, depending on whether thereferenced information is registered in the developer-provided overheadtransmission-line database or the one for users. See Section 5.1 for the available
operations.
To edit previously registered data, select the ‘Edit’ radio button.

To register new data, select the ‘New’ radio button.

After revising or entering the data, click ‘Register’ to register the information in the
database.

To delete registered data, select the ‘Edit’ radio button and click ‘Delete’.

To finish editing, click ‘Exit’.

- 172 -

5.3 Overhead distribution lines
Select ‘Overhead distribution line’ from the ‘Databases’ menu on the menu bar.

The ‘overhead-distribution-line database editing’ dialog appears.

See Section 5.2 for details of how to register information.

5.4 Cables
Select ‘Cable’ from the ‘Databases’ menu on the menu bar.

The ‘cable database editing’ dialog appears.

If one or more external
conductors is set, enter
external conductor

See Section 5.2 for details of how to register information.

- 173 -

5.5 Line/cable database functions
This section describes the line/cable database functions.

SearchThis facility is used to search the databases for lines or cables. Enter the text string
to search for in the ‘Search name’ field, and click ‘Search’. Searches are not casesensitive and blanks are ignored.

The program searches for results containing the entered string. When multiple
search results are returned, clicking ‘Search’ again displays the next search result.
Example: When ‘AC’ was entered as the search string, ‘AC30’ is displayed.

Clicking ‘Search’ again displays the next search result, ‘AC38’.

Display switching buttons
The display switching buttons are used to change the data displayed.
● ［<<］button
Displays the first data.
● ［>>］button
Displays the last data.
● ［<］button- 174 -

Displays the data immediately before the current data.
● ［>］button
Displays the data immediately after the current data.
Track barMoving the track-bar slider right or left scrolls the displayed data forward or
backward. A number can also be entered in the input field, before pressing the‘Enter’ key to display the data at the indicated location.

SliderNumerical input

ImportThis registers user-created line/cable information in CSV format to a database forusers. Overhead lines and cables each use a different file format.
● Import file layout
Overhead lines
Name
Cross-sectional area
Outer diameter
Electrical resistance
Relative magnetic
permeability

CablesName
Number of external conductors
Core wire cross-sectional area
Core wire outer diameterCore wire electrical resistanceCore wire relative magnetic permeability
Flag
Main insulator capacitance, or dielectric constant
Inner semiconductor layer thickness
Outer semiconductor layer thickness
Metal sheath outer diameter
Metal sheath thickness
Metal sheath electrical resistivity
Metal sheath relative magnetic permeability
Cable outer diameter, or metal sheath outer insulator
outer diameter
Metal sheath outer insulator dielectric constant● Items with a pound sign (#) in the first column are treated as comments.
Example#Name, cross-sectional surface area, outer diameter, electrical resistance,
dielectric constantAC 1,27.09,6.9,2.94,1
AC 2,125.5,14.5,0.688,1

ExportThis outputs information registered in a database for users to a CSV-format text file.

- 175 -

- 176 -Appendix 2
XFIT (System Identification Program)
Version 1.30
Instruction ManualCentral Research Institute of Electric Power Industry (CRIEPI)
October, 2021

- 177 -

- 178 -XFIT (System Identification Program for XTAP)Version 1.30
Instruction manualCentral Research Institute of Electric Power Industry (CRIEPI)
October, 2021●

Note that starting with Version 1.20, the file format of the frequency-characteristic data
described in Section 3 of this manual has changed.

1. Overview
XFIT is one of the auxiliary programs accompanying the power system transient analysis program
XTAP (Expandable Transient Analysis Program) developed by CRIEPI. XFIT is a fitting programthat identifies a linear model given numerical frequency-characteristic data. It can identify models
for multiple-input/multiple-output systems (multiple phases in the case of electrical circuit elements).
It can also create an electrical-circuit model that uses the given frequency characteristic as its
admittance frequency response, and use it in XTAP. This program was previously provided as astand-alone program called SysIP (System Identification Program).

2. Linear Model fitting
Multiphase (multiple-input/multiple-output) pole-residue models are linear models fitted toreproduce a frequency characteristic provided in the form of numerical data. In other words, thenumerical data provided follow a model expressed as
N

Rn
ω
− pn
j
n =1

Y ( jω) ≅ ∑(1)

where Y(jω) is the frequency-response matrix provided by the user in the form of numerical data
(in the case of M phases, this is a matrix of size M × M), Rn is the residue matrix (of size M × M),
pn is a pole, and ω is the angular frequency. Models were fitted using a least-squares approach.
See the following references for the detailed procedure.
[1]

[2]

[3]

[4]

CRIEPI Research Report T03013: “A sub-network reduction method for the calculation ofelectromagnetic transients in a power system (Part 1)” [in Japanese] (← Can be downloaded
from the CRIEPI website.)T. Noda, “Identification of a multiphase network equivalent for electromagnetic transient
calculations using partitioned frequency response”, IEEE Trans., Power Delivery, Vol. 20, No.
2, Part 1, pp. 1134-1142, Apr. 2005 (← Can be downloaded from the IEEE website.)T. Noda, “A binary frequency-region partitioning algorithm for the identification of a multiphasenetwork equivalent for EMT studies”, IEEE Trans., Power Delivery, Vol. 22, No. 2, pp. 12571258, Apr. 2007 (← Can be downloaded from the IEEE website.)J. Martinez (ed.) “Power System Transients: Parameter Determination”, CRC Press (← Link

- 179 -

to Amazon listing; the procedure is described in Appendix A of this book.)

3. Frequency-Characteristic Data Preparation(1) The pole-residue models described by Formula (1) are fitted to reproduce a provided numericalfrequency characteristic. This section describes the method for preparing the frequency
characteristic data. XFIT assumes the data are stored in files with the following format:● The numerical data is separated by spaces or tabs.
● If the model to be identified has M phases (M inputs and M outputs) (i.e., the Y(jω) term in
Formula (1) has size M × M), the frequency-characteristic data are stored in M separate files.
● Each file stores the data for one row of Y(jω).
● The number of frequencies must be the same in each of the M data files.
● The data format of the file storing the jth row of Y(jω) is as follows:f(1)mag(1,j,1)phi(1,j,1)

mag(2,j,1)

phi(2,j,1) ･･･ mag(M,j,1)phi(M,j,1)f(2)mag(1,j,2)phi(1,j,2)mag(2,j,2)phi(2,j,2) ･･･ mag(M,j,2)phi(M,j,2)

:

:

:

:

f(k)

mag(1,j,k)phi(1,j,k)mag(2,j,k)

:

:

:

:

f(K)

mag(1,j,K)phi(1,j,K)mag(2,j,K)::phi(2,j,k) ･･･ mag(M,j,k)::phi(2,j,K) ･･･ mag(M,j,K):phi(M,j,k):phi(M,j,K)

where

●
●

f(k) is the kth frequency;
mag(i,j,k) is the amplitude of element (i, j) at the kth frequency;phi(i,j,k) is the phase [deg] of element (i, j) at the kth frequency;
K is the number of frequencies.
Note that this is an updated format created for the current version of XFIT (Version 1.20).

The first few lines of each file can be used freely as a header. Header lines are automaticallyskipped.

- 180 -

4. Five Steps for Model Fitting
Using the XFIT window (shown below), follow the five steps below to fit the model.

Step 1(Section in window: Number of phases)
Specify the number of phases M (‘Nph’ on the screen). M corresponds to the size of Y(jω).
Step 2(Section in window: Frequency response data files)
Specify the M files prepared as described in the last section.
Step 3(Section in window: Error tolerance in relative quantity)
Specify the error tolerance as a relative value (%). This value is used for pole fitting. Specify a value
in the range 0 ≤ EpsR. The default value is 1%.

- 181 -

Step 4
(Section in window: Low level fitting parameters)
Specify detailed parameter settings if necessary. Note that most of these parameters are set todefault values considered to be appropriate, and should not normally need alteration.
●
●
●
●

●
●
●

●

●

Nmin: Start order for an optimal model-order search. (Range: 1 ≤ Nmin ≤ Nmax; Default: 6)
Nmax: Stop order for an optimal model-order search. (Range: Nmin ≤ Nmax; Default: 16)
Nitr: Iteration stop count for a rational function fitting process. (Range: 1 ≤ Nitr; Default: 30)
Nsvd: Constant used in SVD (singular value decomposition) calculations in the least-squares
method. If the number of significant digits in a given value is less than this constant, the value
is removed from the simultaneous equations. (Range: 0 ≤ Nsvd ≤ 16; Default: 2)
symmetric: Flag indicating whether the system to be fitted (i.e., the matrix provided) issymmetric (checked) or asymmetric (unchecked). (Default: checked)
limit poles: If this flag is checked, the poles with an absolute value greater than the maximum
angular frequency are removed. (Default: unchecked)
pole clustering: Flag determining whether or not to consolidate nearby poles into a single pole.
Poles are consolidated when this setting is checked, and kept separate when unchecked.
(Default: unchecked)
EpsP: When the ‘pole clustering’ setting above is checked, any poles within the radius specified
by this parameter are consolidated into a single pole. The value is specified as a relative value(%). (Default: 5%)
outputs: When this flag is checked, intermediate results are output. When not checked,
intermediate results are not output. (Default: checked)

Step 5(Section in window: Start fitting)Press ‘Start’ to begin fitting the model. When it is finished, the ‘ResultViewer’ window opens todisplay the results.

5. Displaying and Saving Identification Results
The ‘ResultViewer’ window shown below opens automatically when model fitting is completed. Thiswindow can be used to display the following graphs:●●

Plot (i,j) element of Y: shows the fitting of model element (i, j). It compares the frequency
characteristic of element (i, j) in the data provided to the frequency characteristic of element (i,j) in the model. The horizontal axis (frequency) may be either linear or logarithmic.
Eigenvalues of Re{Y}: plots the eigenvalues of Re{Y(jω)} versus frequency for the fitted model.
The horizontal axis (frequency) may be either linear or logarithmic. If the eigenvalues ofRe{Y(jω)} are positive for all the frequencies, the fitted model is guaranteed to be positivedefinite (i.e., passive).

- 182 -

The fit results can be saved in the following formats from the ‘ResultViewer’ window:
●

●
●
●

network equivalent in XTAP format: generates and saves data in a format that can be usedfrom a ‘Condensed multiphase circuit model’ (NetEquiv) XTAP part. An admittance elementwith the frequency response fitted by XFIT can be created in an XTAP circuit diagram byplacing a condensed multiphase circuit model in the circuit diagram, double-clicking on it, andusing the window that appears to specify the file generated by this item.
binary format: outputs the identification results as a binary file.
text format: outputs the identification results as a text file.
MATLAB format: outputs the identification results as a MATLAB *.mat file, enabling them to beloaded into MATLAB using the ‘load’ command.

- 183 -

Binary files have the following format:
1) Number of phases M (integer)
2) Number of real poles Nr (integer)3) Number of complex poles Nc (integer)4) Real poles (double; number of values = Nr)
5) Real parts of complex poles (double; number of values = Nc)
6) Imaginary parts of complex poles (double; number of values = Nc)
7) Residue matrix of real poles (double; number of values = M × M × Nr; each matrix row isprovided first, then Nr matrices)
8) Real part of residue matrix of complex poles (double; number of values = M × M × Nc; firsteach matrix row, then Nc matrices)9) Imaginary part of residue matrix of complex poles (double; number of values = M × M ×
Nc; first each matrix row, then Nc matrices)where‘integer’ is an integer type (32-bit)‘double’ is a floating-point real number type (64-bit)- 184 -