# Patent

## Title
Circuit protection and control device simulator

## Abstract

A power circuit protection and control device simulator emulates in real time identical circuit protection and control functions performed by the actual device being simulated and generates real time simulated operational information concerning at least one of the device or the power circuit. A human-machine interface, such as through a web browser, allows a user to input power circuit operational parameters, such as motor current and load, and device variable circuit protection and control operational parameters, such as trip class, ground fault detection or phase unbalance protection. The simulator displays in real time simulated operational information on the human-machine interface. The simulator may be used to simulate operation of an electronic overload relay and an electric motor controlled by the relay.

## Background
CLAIM TO PRIORITY
This application claims the benefit of our U.S. provisional patent application entitled “SYSTEMS, DEVICES, AND/OR METHODS FOR SIMULATING EQUIPMENT” filed May 29, 2008 and assigned Ser. No. 61/056,918, which is incorporated by reference herein.


BACKGROUND OF THE DISCLOSURE
1. Field of the Invention
The invention relates to power circuit protection and control device simulators. One embodiment of the present invention enables a user to simulate actual operation of a motor overload relay and electric motor, via a web browser, using at least some of the identical control parameters of the manufactured relay product. The simulator of the present invention is useful for training users in the operation of a control device and testing simulated operation in a non-destructive virtual environment, without risk of physical damage to actual power equipment. By way of example, a user can test intermittent operation of a simulated motor and overload relay under varying load test conditions envisioned in a future factory design, to determine whether the overload relay will trip due to simulated motor thermal overload, without having to configure an actual motor test bed. The simulator of the present invention also allows non-destructive virtual testing of new control functions, such as new thermal modeling protection algorithms prior to bench testing.
2. Description of the Prior Art
Electrical distribution and power circuit designers, engineers, maintenance technicians, equipment specification/purchasing managers and others in the field need to understand the features, functions and operational characteristics of residential, commercial and industrial electrical equipment. Given the complexities of modern electrical equipment components and electrical distribution system design environments, it is desirable to understand, prior to actual construction, how equipment will interoperate once connected to a working system.
In the past, longer construction lead times and relatively fewer variations of relatively simpler electrical equipment allowed designers to use best professional judgment and experience to design and specify electrical distribution systems. In due course, the system would be built and “de-bugged” as necessary in the field in order to achieve acceptable operational performance. Present shorter design and construction lead times, greater variation and complexity of equipment, and high repair and replacement cost of electrical equipment have created demand for pre-construction system performance verification.
One common electrical power system application in industrial and commercial environments is an electrical motor powering an intermittent, varying load. A motor overload relay is interposed between an electrical power source and the motor in order to protect the motor from overload conditions, such as a stalled or locked rotor, and overheating from excessive or rapid intermittent loads that do not allow the motor to cool sufficiently. The overload relay is sized, through equipment performance specification, control settings (i.e., maximum rated steady-state operational, maximum in-rush current during startup, permissible phase unbalance variations, etc.) and empirical testing, to protect the motor from overheating, yet avoid inadvertent nuisance tripping.
In the past, through professional judgment, experience and trial and error, an electrical system designer would attempt to match a motor and overload relay combination to be able to conform to the anticipated system design operational requirements. The designer could consult product specification sheets, time vs. current heat charts and the like to specify a particular rating and adjustment settings of a motor overload relay. Product specification, testing and configuration were heavily dependent upon the empirical experience of the designer. Upon actual construction, the combination would be tested and verified in the field. If the system overheated or was subject to nuisance tripping, different overload relay control adjustment settings would be tested. If performance remained unsatisfactory a different specification overload relay might be needed to replace the one in the initial design.
The time-consuming trial and error specification methodologies and development of designer professional experience had to be passed on to designer trainees. Need has long existed in the electrical system design arts to provide simulation training tools that would enable experienced design professionals to configure system designs in quicker fashion with minimal design corrections and to provide training experience for less experienced design trainees.
In the past there have been attempts to make electrical distribution circuit protection simulation apparatus that would enable a designer to mimic loads on multiple circuit breakers in a distribution system, so that faults could be isolated to the circuit breaker most closely associated with the fault node. Such systems essentially allowed computer-stored time/current charts to be overlayed, so that the correct circuit breaker size could be verified, as well as overload current settings (e.g., ground fault, instantaneous trip and other time/current settings). Time/current data were generally gathered empirically. For example, for a specific design and load capacity of an electric motor, acceptable performance time/current charts were derived so that motor heat capacitance operational limits were understood by designers. Generally such charts were created with conservative operational parameters, so as to minimize risk of motor damage.
As motor control electronics became more sophisticated, microprocessor-controlled overload relays were developed that could digitally model electrical motor heat capacitance and heat transfer in real time. An example of such motor controllers is described in U.S. Pat. No. 5,539,601, “Apparatus and Method for Thermal Protection of Electric Motors”. Motor temperature overload control algorithms described in the patent allowed for more precise, real time evaluation of motor heat capacitance and heat transfer. Rather than select conservative control settings based on imperfect empirical data, the motor controller could more successfully model actual motor operating conditions, and if necessary cause a motor contactor to de-energize power to the motor before the motor became overheated. However, motor controllers of the type shown in U.S. Pat. No. 5,539,601 were intended for field application and not as virtual simulator test beds. Both the control algorithms and control settings had to be bench or field tested. It is desirable to confirm operability of control algorithms and control settings prior to bench testing or field installation.
Thus, a need exists in the art for an electrical power distribution system circuit protection and control simulator that enables designers to test and verify system designs and equipment configuration virtually. A need also exists in the art for an electrical power distribution system circuit protection and control simulator that enables design and maintenance professionals to learn about the interoperability, compatibility and operational characteristics of components in a “hands on” virtual environment.
SUMMARY OF THE INVENTION
These and other needs are achieved in accordance with the present invention by a power circuit protection and control device simulator that emulates in real time identical circuit protection and control functions performed by the actual device being simulated and generates real time simulated operational information concerning at least one of the device or the power circuit. A human-machine interface, such as a web browser, allows a user to input power circuit operational parameters, such as motor current and load and device variable circuit protection, as well as control operational parameters, such as trip class, ground fault detection or phase unbalance protection. The simulator displays in real time simulated operational information on the human-machine interface. The simulator may be used, for example, to simulate operation of an electronic overload relay and an electric motor controlled by the relay. Desirably the simulator is implemented on a web browser for easy use and application by electrical equipment design and maintenance professionals. The simulator of the present invention may be implemented in a client-server networked computer environment.
The present invention includes a power circuit protection and control device simulator having a processor. Memory, accessible by the processor, stores instructions executable by the processor to emulate in real time identical circuit protection and control functions performed by the actual device and generate real time simulated operational information concerning at least one of the device or the power circuit. A human-machine interface, such as a personal computer display, is coupled to the processor and is used for inputting to the processor at least one power circuit operational parameter and at least one variable circuit protection and control operational parameter performed by the actual device. The processor in turn emulates in real time the circuit protection and control functions based on user inputted parameters and displays in real time simulated operational information on the human-machine interface.
In one exemplary application, the simulator device can simulate an electronic motor overload relay and an electric motor. In this application all overload relay operation parameters can be simulated, including: motor load, motor phase unbalance percentage, phase loss, ground fault, full load current, continuous motor operation or intermittent motor operation. Circuit protection and control functions performed by the actual overload relay device are simulated, and include any one of motor overload, thermal overload, short circuit, ground fault or phase unbalance protection or heat capacitance/transfer thermal modeling algorithms. The simulation models employ the actual control algorithms of the real overload relay.
The present invention includes by way of example methods for operating the exemplary overload relay simulator, described above, including inputting to the processor with the human-machine interface at least one power circuit operational parameter and at least one variable circuit protection and control operational parameter performed by the actual device, with the processor, emulating in real time at least one protection and control function performed by the actual device and generating real time simulated operational information concerning at least one of the device or the power circuit. Thereafter the simulated operational information is displayed on the human-machine interface.
Desirably, the simulator of the present invention may include an additional reset feature that enables reset of the thermal modeling simulation, so that additional simulations may be run on a virtual “cooled-down” motor, without the need to wait for additional real time to allow for motor cooling, as would be done in an actual overload relay installed in a field application.



BRIEF DESCRIPTION OF THE DRAWINGS
The teachings of the present invention can be readily understood by considering the following detailed description in conjunction with the accompanying drawings, in which:
FIG. 1 shows a software block diagram of an exemplary embodiment of the simulator of the present invention;
FIG. 2 shows an exemplary embodiment of the human-machine user interface of the simulator of the present invention, displaying a motor overload relay and electric motor prior to initialization of a simulation by a user;
FIG. 3 shows an exemplary embodiment of the human-machine interface of the simulator displaying a motor overload relay and electric motor simulation in progress; and
FIGS. 4-15 show an exemplary embodiment of the human-machine interface of the simulator displaying screen shots of step-by-step tutorial information window instructions for using features of the simulator.



To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures.
DETAILED DESCRIPTION
After considering the following description, those skilled in the art will clearly realize that the teachings of the present invention can be readily utilized in simulators for other electrical power distribution system circuit protection and control equipment.
1. Simulator Architecture
Referring to the drawings, FIG. 1 is a block diagram of an exemplary embodiment of the simulator 100 of the present invention. The simulator 100 includes an information device 110 that in certain operative embodiments can comprise a computer server, a web server, personal computer, work station or personal digital assistant. The information device 110 includes a processor 120 and memory 130 accessible by the processor. The memory 130 can be any form of volatile or non-volatile electronic memory that is capable of storing analog or digital information. The memory 130 stores instructions 140 executable by the processor 120 in order to emulate in real time identical circuit protection and control functions performed by the actual device, e.g., an electronic overload relay for an electric motor with motor thermal protection functions. The information device 110 has an input/output (I/O) device 150 that is capable of communicating with one or more types of interface devices, discussed below.
The information device 110 of the exemplary embodiment shown in FIG. 1 also may have a network interface 160 for communication with one or more networks 170 and other devices 172 in communication with the network. The device 110 may be a server, including a web server that is in communication with client computers 172 via hard wired communication pathways or in a wireless communication network exemplified by receiver/transmitter 174 in communication with a wireless communication capable computer 176 or wireless personal digital assistant (PDA) 178. The network 170 may also include a local area network (LAN), wide area network (WAN), and the Internet. The simulator 100 desirably can be run in a browser and/or other web-enabled environment, including various forms of JAVAscript-enabled software, or FLASH® player environments, such as those offered by Adobe Systems. Alternatively, the simulator 100 may be a stand-alone system, such as a personal computer, that does not communicate with other devices during simulations.
The I/O device of information device 110 communicates with one or more human-machine user interfaces 200, that in exemplary embodiments can include a visual display, keyboard and cursor control mouse (not shown). The information device 100 can comprise any of numerous circuits and/or components, such as for example, one or more network interfaces 160, one or more processors 120, one or more memories 130 containing instructions 140, one or more input/output (I/O) devices 150, and/or one or more user interfaces 200 coupled to I/O device 150. In certain exemplary embodiments, via one or more user interfaces 200, such as a graphical user interface, a user can view a rendering of information related to specifying, ordering, designing, selling, manufacturing, and/or delivering a product, such as an electric motor and/or devices associated therewith.
2. Simulator Human-Machine User Interface
FIGS. 2-15 show an exemplary simulator embodiment displayed on human-machine user interface 200 computer display screen that is configured to simulate the Siemens ESP200 NEMA solid-state overload relay 205, sold in the United States of America by Siemens Energy & Automation, Inc. of Alpharetta, Ga. In this simulator screen 200 embodiment, the overload relay 205 is protecting a three phase, NEMA rated electric motor 215. As can be appreciated by those skilled in the art, the simulator of the present invention can be configured to simulate other types of circuit protection and control devices in power distribution circuits and protected electrical components other than motors, and the arrangement of display 200 features can be varied. For example, the display 200 may include a tutorial or other information window 220 for the benefit of users.
In this exemplary embodiment of the simulator, shown in FIG. 2, the user can enter and/or specify any combination of the following circuit protection and control operational parameters through manipulation of a screen cursor via a computer mouse, as if the user were actually configuring an actual Siemens ESP 200 overload relay 205 control switches and buttons:

    
    
        Trip Class DIP switches 206 (e.g., 5, 10, 20, 30);
        Phase Unbalance DIP switch 207 (e.g., On or Off);
        Phase Loss DIP switch 208 (e.g., On or Off);
        Reset Mode DIP switch 209 (e.g., Manual or Automatic);
        Ground Fault DIP switch 210 (e.g., On or Off);
        Full Load Amps via rotary selector 211 (e.g., 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 amps); and
        Overload relay reset button 212.
    
    


Additionally, the power circuit operational parameters can be adjusted by the user through manipulation of motor operation environment screen 200 fields via a computer mouse, such as:

    
    
        Motor load (L1) slider bar 225 (e.g., 0-85 A);
        Phase balance slider bar 230 (e.g., 0-100%), where 100% means fully balanced, all phases equal;
        Motor START button 235;
        Motor STOP button 240;
        Motor starter duration condition highlighted button 245 (e.g., Momentary start or Maintained, repeated start);
        RESET THERMAL MEMORY button 250;
        SIMULATE GROUND FAULT button 255; and
        SIMULATE PHASE LOSS button 260.
    
    


As shown in FIGS. 2 and 3, an exemplary simulation run display screen 200 can show simulated power circuit (e.g., motor 215) operational status information, including:

    
    
        show the motor in “run” and/or energized mode versus “off” mode via a red or green light and/or dot 265;
        display the motor's shaft 270 slowly turning;
        indicate the Motor Status 275 as “OFF’ or “RUNNING”;
        present the motor's Runtime in seconds 280;
        show the motor's Trip Status 285;
        show the overload relay AUTO RESET delay in seconds 290;
        indicate a simulated Thermal Memory value 295 (i.e., percentage of allowable stored heat capacitance in the motor);
        display the load amps on each phase 300; and
        display the full load amps (FLA) multiple 305.
    
    


Note that this particular exemplary Siemens ESP 200 overload relay simulator display 200 of FIGS. 2 and 3 only simulates overload relay class 48, with a relay current range of 3-12 A. As those skilled in the art can appreciate, in this overload relay class, the current transformer ratio is 2600 and the burden resistor is 26.10 ohms.
FIGS. 3-15 show exemplary screen 200 step-by-step tutorial information window 220 instructions for using the overload relay 205. In these figures, the simulator is simulating a Siemens ESP200 overload relay. Screen 220-0 is an overview introductory message. Screen 220-1 suggests that the user adjust initial control parameter settings on the simulated overload relay 205 with a computer mouse. Screen 220-2 teaches the user how to simulate an overload condition, and screen 220-3 teaches resetting the relay 205 after a simulated overload condition.
The principles of thermal memory (i.e., motor retained heat capacitance and heat transfer) are taught in screen 220-4. Note that the availability of the RESET THERMAL MEMORY button 250 feature allows the user to wipe the thermal memory to simulate motor cooling to ambient temperature so that the user may promptly re-initiate simulated motor operation. Without this feature the motor thermal modeling algorithms utilized in the real Siemens ESP200 overload relay would not allow a real motor to start until sufficient time has elapsed to allow for ambient motor cooling.
Simulated phase loss and ground fault are taught in screens 220-5 and 220-6, respectively. Relay 205 auto reset features are taught in screens 220-7 and 220-8. Phase unbalance protection and control features are taught in screens 220-9 and 220-10. Screen 220-11 invites the user to experiment with the overload relay control settings and different motor operational parameters for additional training and familiarization.
3. Simulator Operation
The simulator 100 instructions 140 stored in the memory 130 enable processor 120 to emulate in real time the circuit protection and control functions performed by the actual device being simulated, based on user-inputted protection settings and power circuit operational parameters. Simulator 100 operation will now be explained with reference to the exemplary Siemens ESP200 overload relay described above and the user interface 200 configuration settings shown in FIGS. 2 and 3.
Once the user clicks on the START button 235, the simulator 100 can then calculate the simulated motor currents, as follows:

    
    
        L1 specified by user (slider bar 225)
        L2=L1
        L3=L1* Phase Balance specified by user
    
    


For each of the motor's 3 phases, the simulator 100 can calculate N, the thermal increment per time period, from the following equation:




  
    N
    ⁡
    
      (
      
        L
        ⁢
        
          
        
        ⁢
        1
      
      )
    
  
  =
  
    
      
        I_Motor
        ⁢
        
          (
          
            L
            ⁢
            
              
            
            ⁢
            1
          
          )
        
        ×
        R_Burden
        ×
        
          2
        
      
      
        n_current
        ⁢
        _transformer
        ×
        π
        ×
        510
        ⁢
        
          
        
        ⁢
        k
        ⁢
        
          
        
        ⁢
        Ω
        ×
        4
        ⁢
        
          
        
        ⁢
        μA
      
    
    ×
    9450
  




where:

    
    
        N(Lx)=the thermal increment per time period for the specified phase;
        I_Motor(Lx)=the motor current (amps) for the specified phase;
        R_Burden=the burden resistance, which can depend on the overload relay class;
        N_current_transformer=current transformer ratio, which can depend on the overload relay class; and
        the 510 kΩ value, 4 μA value, and 9450 constant are associated with this model overload relay.
    
    


The simulator 100 can then calculate A_max, the maximum periodic thermal increment from the following equation:

A_max=max(N(L1),N(L2),N(L3))

The simulator 100 can then calculate P_Max, which can reflect the motor current unbalance and is zero if the phase balance is 100%, from the following equation:

P_max=max(abs(N(L1)−N(L2)),abs(N(L2)−N(L3)),abs(N(L3)−N(L1)))

Next the simulator 100 looks up Tw from the following table stored in memory 130, which can recalibrate the algorithm to execute once each 500 milliseconds versus the original 192 milliseconds, and/or can alter the calculation to account for the Trip Class for this particular overload relay.














Trip class
Tw



















5
2.9



10
2.9/2



20
2.9/4



30
2.9/6










Using the full load amperage (FLA) value specified by the user with selector switch 211, the simulator 100 can select a threshold from the following table:














FLA
Threshold



















3
4832



4
6368



5
7936



6
9616



7
11344



8
13024



9
14544



10
16240



11
17648



12
19168










Next, the simulator 100 can iteratively calculate motor model (“MM”) values at each 500 millisecond interval, as shown in the following equations. This calculation can estimate the exponential heating effects of the current flowing through the motor 215. If the MM value exceeds the threshold, the simulator 100 can simulate a trip of the overload relay 205. When the relay 205 trips, the simulator 100 can drop the motor current to zero and the calculated MM value can gradually decrease, just as would occur in an actual motor.

MM—0=0

MM—1=MM—0+Tw*(−MM—0/128+A_max/2+P_max/4)

MM—2=MM—1+Tw*(−MM—1/128+A_max/2+P_max/4)

MM—3=MM—2+Tw*(−MM—2/128+A_max/2+P_max/4)

And so on.
When, for example, the phase unbalance is to approximately 70% or greater and the value of the phase loss variable is switched to “On” (DIP switch 208), the simulator 100 can simulate a phase loss and an associated trip. Likewise, when, for example, the value of the ground fault variable is switched to “On” (DIP switch 210), the simulator can simulate a ground fault by pressing SIMULATE GROUND FAULT button 255 and thereby initiate a simulated associated trip.
Thus, after clicking the START button 235, the user can observe the motor control indicators for values generated by the simulator, including load amps 300, full load amperage (FLA) multiple 305, motor status 275, motor run time 280, trip status 285, auto reset time 290 and thermal memory percentage 295.
Although various embodiments which incorporate the teachings of the present invention have been shown and described in detail herein, with respect to an exemplary motor overload relay and electric motor simulator, those skilled in the art can readily devise many other varied simulator embodiments for other circuit protection and control devices and other electrical equipment within a power circuit that still incorporate these teachings.

## Claims

1. A simulator for a power circuit protection and control device comprising:
a processor;
memory coupled to the processor, the memory storing instructions executable by the processor to simulate in real time an operation of the power circuit protection and control device and to simulate in real time a coupled power circuit, the simulator replicating at least one circuit protection and control function performed by a non-simulated power circuit protection and control device;
a human-machine graphical user interface coupled to the processor for inputting to the simulator at least one operational parameter of the power circuit and at least one operational parameter of the non-simulated power circuit protection and control device; and
wherein the processor simulates in real time the at least one circuit protection and control function based on the inputted parameters, generates in real time simulated operational information of the circuit protection and control device and displays the real time simulated operational information on the human-machine graphical user interface.

2. The simulator of claim 1, further comprising a simulation reset device, operable through the human-machine graphical user interface, for causing the simulator to selectively reset initial operating conditions of the power circuit protection and control device.

3. The simulator of claim 1, wherein the circuit protection and control device is an electronic motor overload relay, the simulated power circuit includes an electric motor, and the power circuit operational parameter includes one of a motor load, a motor phase unbalanced percentage, a phase loss, a ground fault, a full load current, or a continuous or intermittent motor operation.

4. The simulator of claim 3, wherein the input at least one operational parameter of the non-simulated power circuit protection and control device includes one of a motor overload, a thermal overload, a short circuit, a ground fault, a phase unbalance protection or a thermal model.

5. The simulator of claim 1, wherein the human-machine graphical user interface includes a media player software application operating within a web browser.

6. The simulator of claim 1, wherein the memory also stores instructions executable by the processor to display on the human-machine graphical user interface step-by-step instructions on how to use the simulator.

7. The simulator of claim 1, wherein the processor and the coupled memory is included within a web server that is in communication with a software application within a web browser, the software application within the web browser including the human-machine graphical user interface for inputting the at least one operational parameter of the power circuit and the non-simulated circuit protection and control device, the web server communicating the real time simulated operational information to the software application within the web browser.

8. A simulator for a power circuit protection and control device comprising:
a processor;
memory coupled to the processor, the memory storing instructions executable by the processor to cause a software application operating within a web browser to simulate in real time the operation of the power circuit protection and control device and to simulate in real time a coupled power circuit, the simulator replicating at least one circuit protection and control function performed by a non-simulated power circuit protection and control device;
a graphical user interface within the software application for inputting to the simulator at least one operational parameter of the power circuit and at least one operational parameter of the non-simulated circuit protection and control device; and
wherein the processor simulates in real time the at least one circuit protection and control function based on the input operational parameters, generates in real time simulated operational information of the circuit protection and control device, and displays the real time simulated operational information within the web browser.

9. The simulator of claim 8, further comprising a simulation reset device, operable through the human-machine graphical user interface, for causing the simulator to selectively reset initial operating conditions of the power circuit protection device.

10. The simulator of claim 8, wherein the circuit protection and control device is an electronic motor overload relay, the simulated power circuit includes an electric motor, and the power circuit operational parameter includes one of a motor load, a motor phase unbalanced percentage, a phase loss, a ground fault, a full load current, or a continuous or intermittent motor operation.

11. The simulator of claim 10, wherein the input at least one operational parameter of the non-simulated power circuit protection and control device includes one of a motor overload, a thermal overload, a short circuit, a ground fault, a phase unbalance protection or a thermal model.

12. The simulator of claim 8, wherein the software application operating within a web browser is a media player software application.

13. The simulator of claim 8, wherein the memory also stores instructions executable by the processor to display on the human-machine graphical user interface step-by-step instructions on how to use the simulator.

14. The simulator of claim 8, wherein the processor and the coupled memory is included within a web server that is in communication with the software application operating within the web browser, the software application within the web browser for inputting the at least one operational parameter of the circuit protection and control device to the web server and the web server communicating the real time simulated operational information to the software application operating within the web browser.

15. A method for simulating the functioning of a circuit protection and control device the method performed by a simulator for simulating in real-time the operation of the circuit protection and control device and for simulating in real time a coupled power circuit, the simulator replicating at least one circuit protection and control function performed by a non-simulated power circuit protection and control device, the simulator having a processor, an associated memory for storing instructions executable by the processor to perform the simulation and information generation functions, and a human-machine graphical user interface coupled to the processor, the method comprising:
inputting to the processor with the human-machine graphical user interface at least one operational parameter of the power circuit and at least one operational parameter of the non-simulated circuit protection and control device;
with the processor,
simulating in real time at least one protection and control function performed by the circuit protection and control device;
generating real time simulated operational information concerning the circuit protection and control device; and
displaying the real time simulated operational information with the human-machine graphical user interface.

16. The method of claim 15 further comprising selectively resetting the simulator to restore initial operating conditions to the circuit protection and control device.

17. The method of claim 16, wherein the step of resetting includes resetting a thermal model associated with the power circuit.

18. The method of claim 15 wherein the circuit protection and control device is an electronic motor overload relay and the power circuit includes an electric motor and wherein the power circuit operational parameters include one of a motor load, a motor phase unbalanced percentage, a phase loss, a ground fault, a full load current, or a continuous or intermittent motor operation.

19. The method of claim 18, wherein the input at least one operational parameter of the non-simulated power circuit protection and control device includes one of a motor overload, a thermal overload, a short circuit, a ground fault, a phase unbalance protection or a heat thermal model.

20. The method of claim 15, wherein the display step is performed in connection with a software application operating within a web browser.

21. The method of claim 15 further comprising displaying step-by-step instructions on how to use the simulator on the human-machine graphical user interface.

22. The method of claim 15, wherein the simulation is performed on a web server incorporating the processor and the human-machine graphical user interface is used to input the at least one power circuit operational parameter and the at least one operational parameter of the circuit protection and control device to the web server, and the web server communicates the real time simulated operational information to the human machine graphical user interface.