General Overview

System Engineering Research Laboratory
Brief Overview
The System Engineering Research Laboratory has been contributing to the development of the electric power industry andsociety through research, development, experiment and evaluation of (i) planning, operation, control and analytical technologies
regarding electric power generation systems including distributed generators, transmission systems, distribution systems, communication systems and information systems and (ii) end-user technologies to ensure the efficient use of electricity.

Achievements by Research Theme
System analysis and stability assessment[Objectives]
To contribute to the maintenance and development of the fundamental power system technologies which meets both theefficiency and stability requirements through (i) the advancement of system analysis technologies to secure power system stability andthe transparency and economy of operation and (ii) the development of on-line system operation support technologies[Principal Results]
・ An accurate power system demand prediction method in several tens of minutes ahead using on-line data was developed to estimate
loads flow conditions for the short-term system stability evaluation. In regard to the equivalent reduction of external systems, whichis important for the on-line stability evaluation, an accurate reduction technique reproducing multiple oscillation modes of a powersystem was developed (Fig. 1).
・ To develop a practical simulation technique for the dynamic system characteristics at the time of changing supply and demandcondition, the long-term dynamic system analysis technique was improved. In addition, functions of the CRIEPI’s power systemanalysis tools (CPAT)were enhanced.
Impact assessment of wind power generation on a power system[Objectives]
To develop a system analysis model for wind power generation, to extract the characteristics of the output fluctuations ofwind power generation and to develop a battery control technology for leveling the output in order to accurately analyse and reducethe impacts of wind power generation on the power system[Principal Results]
・ For evaluation of the impacts of wind power generation on the power system, a model was developed to simulate the dynamic
performance of constant speed and variable speed wind power generators, including their prime movers.
・ For evaluation and prediction of the output of power generation, the meteorological factors with a significant impact on the fluctuation of the wind power generation output were identified through case studies.
System monitoring and control network[Objectives]
To develop basic technologies for a system control communication network capable of gathering on-line detailed data on thesystem conditions in a wide area and of conducting high speed control during normal operation or system failure[Principal Results]
・ A scenario was developed with the participation of power companies, concerning how to apply an adaptation function middlewareand a security function to the distributed real-time computer network architecture (DRNA) proposed by the CRIEPI to deal withproblems for practical application.
・ The effectiveness of the method to configure a reliable and efficient large-scale IP network was confirmed with a validation test
using commercial equipment. A prototype was designed for a horizontally distributed emergency control network using IPtechnologies.
Communication media and network technology[Objectives]
To secure communication media and network technologies required for the maintenance of electrical power apparatus in
power companies and to develop control technologies and propagation characteristic analysis technologies for a future communica-18

System Engineering Research Laboratorytion system for the power industry[Principal Results]
・ To efficiently establish a sensor network at system maintenance sites with the minimum resources, a technique was developed toassist the optimum allocation of sensor nodes while automatically collecting their fundamental transmitting performance data forradio signals.
・ To enable wide band wireless access to system maintenance locations, an efficient technique using the optical wavelength control
technology was developed to configure a radio-on-fiber network to transmit millimeter wave signals via optical fibre. In addition, asimple technique was developed to estimate the required communication bandwidth satisfying the delay time conditions using IP
traffic monitoring data.
Information technology[Objectives]
To develop fundamental information technologies for maintenance of the reliability and cost reduction of the electricity
business using IT-equipments and expertise in related domain.
[Principal Results]
・ To ensure the effective use of site-monitoring cameras installed at electrical facilities, images taken by monitoring cameras underdifferent conditions (weather, day or night and moving object, etc.) were used to check the detection accuracy of the moving object
detection method developed by the CRIEPI. It was confirmed that this technique using images taken by monitoring cameras havesatisfactory detection accuracy for practical use.
・ A new technique was developed to pick up signs of unusual conditions of bearing vibration in hydor-power plant using the patternrecognition technology so that rare occasions of power equipment abnormality can be detected at an early stage.

The oscillation mode of the original
system is identified using the timeseries analysis technique. The
parameters of the generator's
excitation system on the reduced
system is then tuned to preserve thedominant mode.

外部系統<ExternalSystems>
Several hundred
発電機
数百機
generators<Own
System>自社系統

1.5Base station<OwnSystem>
自社系統

G1

1.0

G2

PSS

Millimeter waveband
radio-on-fiber accessnetwork

G3

PSS

PSS

0.5

Connected to avideo camera or0.0

simplification of the central
station by means of controlling
Central station the wavelength of light

従来縮約

Conventional method-0.5

Support for field work bychecking with themaintenance record, etc.
using a radio terminal

CameraReductionof external
外部系統を縮小
system

2.0

Tie line power flow (p.u.)

Large capacitytransmission using
millimeter wave

Original system

原系統

Newly developedmethod
開発手法

Optical fiberMillimeter wave radio signal

-1.0
0

1

2

34

Intra network

5Communication with remotesites using videoTime(sec)Fig.1 System Reduction Technique appliable

Fig.2 Millimeter Waveband Radio-on-to Multiple Oscillation Modes

FiberNetwork

19B