Lab 3: Dynamical Modeling and Simulation of 4-Bus Power System

using PSS®E

Aim:

The main objective of this activity is to be familiarized with dynamical modeling of small

power systems using PSS®

E program. This will help the students to do the analysis for large-

scale power system in Lab 2.

Network Data:

Consider the following power network:

Consider bus-1 as infinite bus, bus-2 as generator bus, bus-3 & bus-4 as load bus. Consider

base MVA as 100 MVA, base frequency as 50 Hz, and based voltage as 11 kV.

Data for Static Modeling

Generator data: MW and pu

Load data: MW and MVAr; MW and MVAr

Infinite bus data: pu and

Transformer data: pu and pu

Transmission line data: pu and pu

Fixed shunt: 250 MVAr

Data for Dynamic Modeling

For Dynamic Modeling: , , , s

Excitation System Data: s, s, , ,

Governor Data: , s, s, s,

Dynamical Modeling:

Please use the following steps:

Step 1: Creating a dynamic file with “.dyr” extension

In this step, first create a “.txt” file follows:

Rename the file as follows:

Here you can use any name but the extension will be “.dyr”. Now the following window will

appear:

This will create the following “.dyr” file:

If you are unable to open the file, try to open with notepad.

Step 2: Familiarizing with dynamical model in PSS®E:

In this step, it is essential to use the dynamical data of the generation systems. The generation

system includes generator dynamics, excitation system dynamics, and turbine-governor

dynamics.

Please keep in mind that the generator with infinite bus does not include any excitation and

turbine-governor system.

Now let’s familiarize with the different generator models in PSS®E. If you GO to

Start Menu>All Programs>Siemens PTI> PSSE University 33>PSS®E Documentation>

Documentation

The following window will appear:

Then click on the Model Library as highlighted above and you will see the following pdf

window:

From the left side of the above window, you can see different data sheet for different

components.

If you will click on Chapter 1, you will see the following window:

This window shows different types of generators. The highlighted generators are the most

commonly used synchronous generators in power systems.

Please keep in mind that for infinite bus we always use classical generators “GENCLS”.

The other generators are normally chosen as suggested by the system operators or based on

the available data which mostly fit with the model data. We mostly use either “GENTRA” or

“GENROU”. For the considered example we will use “GENTRA” and for lab2

“GENROU”.

If you will click on Chapter 6, you will see the following window:

This window shows different types of excitation systems. The highlighted excitation systems

are the most commonly used with synchronous generators in power systems.

Please keep in mind that for infinite bus, we normally don’t consider any excitation system.

The exciters are also chosen as suggested by the system operators or based on the available

data which mostly fit with the model data. We mostly use either “ESAC4A” or “ESST1a”.

For the considered example we will use “ESAC4A”.

If you will click on Chapter 7, you will see the following window:

This window shows different types of turbine-governor systems. The highlighted turbine-

governor systems are the most commonly used with synchronous generators in power

systems.

Please keep in mind that for infinite bus, we normally don’t consider any turbine-governor

system.

The turbine-governor are chosen as suggested by the system operators or based on the

available data which mostly fit with the model data. We mostly use either “TGOV1” and for

the considered example and Lab 2, we will use “TGOV1”.

If it is advised to use power system stabilizer, then you need to click on Chapter 3. We

normally use STAB1.

Step 3: Putting data into “.dyr” file and building dynamical model:

Here, we need the put the following information into “.dyr” file:

1. Infinite bus data (as GENCLS)

2. Generator data:

a) Generators data (as GENTRA)

b) Exciter data (as ESAC4A)

c) Turbine-governor data (as TGOV1)

Putting GENCLS into “.dyr” file:

Open the following file and click on GENCLS as highlighted

After clicking “GENCLS”, you will see the following window:

You have to put the data in the sequence as highlighted in light RED.

Here:

IBUS= The bus number at which the infinite bus or classical generator is connected which is

“1” for the example

GENCLS= Represents the type of generator which will remain unchanged

ID= This is the bus ID which can be found from the network data when we did load flow last

week. This is “1” for this example which can be seen as follows from “Machine” tab.

CON (J) and CON(J+1)= Represents the values of H & D respectively which is obvious

from the table above as highlighted in orange color. These values are normally zero for

infinite bus system.

Therefore, the dynamic data for infinite bus can be put into the “.dyr” file as follows:

1, ‘GENCLS’, 1, 0 0/

Putting GENTRA into “.dyr” file:

Open the following file and click on GENTRA as highlighted

After clicking “GENTRA”, you will see the following window:

You have to put the data in the sequence as highlighted in light RED.

Here:

IBUS= The bus number at which the generator is connected which is “2” for the example

GENTRA= Represents the type of generator which will remain unchanged

ID= This is the bus ID which can be found from the network data when we did load flow last

week. This is “1” for this example which can be seen as follows from “Machine” tab.

CON (J) to CON(J+8)= Represents the values of generator parameters which is obvious

from the table above as highlighted in orange color. These values need to put in a sequence as

shown in the highlighted table.

Therefore, the dynamic data of the generator used in this example can be put into the “.dyr”

file as follows:

2, ‘GENTRA’, 1, 8 3.5 4 2.1 2.1 0.4 0 0 0/

The RED values are not provided in the example and they are assumed as zero. In this case,

the “.dyr” file will be updated as follows:

Putting ESAC4A into “.dyr” file:

Open the following file and click on ESAC4A as highlighted

After clicking “ESAC4A”, you will see the following window:

You have to put the data in the sequence as highlighted in light RED.

Here:

IBUS= The bus number at which exciter is connected which is “2” for the example

ESAC4A= Represents the type of exciter which will remain unchanged

ID= This is the bus ID which can be found from the network data when we did load flow last

week. This is “1” for this example which can be seen as follows from “Machine” tab.

CON (J) to CON(J+9)= Represents the values of excited parameters which is obvious from

the table above as highlighted in orange color. These values need to put in a sequence as

shown in the highlighted table.

Therefore, the dynamic data of the generator used in this example can be put into the “.dyr”

file as follows:

2, ‘ESAC4A’, 1, 0.03 5 -5 0 0 200 0 5 -5 0/

The RED values are not provided in the example and some of they are assumed as reasonable

values and others as zero. In this case, the “.dyr” file will be updated as follows:

Putting TGOV1 into “.dyr” file:

Open the following file and click on TGOV1 as highlighted

After clicking “TGOV1”, you will see the following window:

You have to put the data in the sequence as highlighted in light RED.

Here:

IBUS= The bus number at which turbine-governor is connected which is “2” for the example

ESAC4A= Represents the type of turbine-governor which will remain unchanged

ID= This is the bus ID which can be found from the network data when we did load flow last

week. This is “1” for this example which can be seen as follows from “Machine” tab.

CON (J) to CON(J+6)= Represents the values of turbine-governor parameters which is

obvious from the table above as highlighted in orange color. These values need to put in a

sequence as shown in the highlighted table.

Therefore, the dynamic data of the generator used in this example can be put into the “.dyr”

file as follows:

2, ‘TGOV1’, 1, 0.05 0.5 50 -50 0.24 0.8 0/

The RED values are not provided in the example and they are assumed as zero. In this case,

the “.dyr” file will be updated as follows:

Finally save the file in the same directory where you build the static model.

If additional dynamical elements such stabilizers are required to model, you have to add that

into the same “.dyr” file.

Now the dynamical model of the system is done.

Dynamic Simulation and Fault Analysis:

1. Build the static model of the system using the data as provided in this sheet.

2. Conduct load flow using any method on the static model as you did in lab 0. Go to Power

Flow -> Solution->Solve or CTRL+Shift+S or use the icon, and use the default values

to solve the case. Check in the Output Bar that the solution has converged.

3. Now convert the load and generator to Norton equivalents, go Power Flow->Convert

Loads and Generators as follows:

4. Now click Convert Generators and Convert Loads boxes. Finally click on Convert as

shown below:

5. Go to Power Flow > Solution> Order network for matrix operation (ORDR) as

follows:

Then the following window will appear

Select as shown in the above figure and click on “OK”.

6. Go to Power Flow > Solution> Factorize admittance matrix (FACT) as follows:

7. Go to Power Flow > Solution> Solution for switching studies (TYSL) as follows

The following window will appear

Select as shown in the above figure and click on “OK”.

8. Now open the “Apel.dyr” file where you will see the following window:

Here before clicking “OK” you need put three compiler files: CC1, CT1, and Compile. These

files can be downloaded from the blackboard.

You have to save these compiler files in the same directory where you have saved the “.sav”,

and “.dyr” files.

For CONEC, the compiler is CC1.flx

For CONET, the compiler is CT1.flx

For Compile, the compiler is Compile.bat

9. After putting all compiler files, press ‘OK’. Now you will see the following window.

If you don’t see “GENCLS”, “GENTRA”, “ESAC4A”, “TGOV1” or whatever you put in

the dyr file, your dynamical modeling is WRONG.

At this stage, the system is ready for dynamical simulation. However, before doing the

simulation, you need to select the simulation channel through which you can look at the

response of the system. To do this, follow the instruction as shown below:

10. Select the simulation channel as

You can select any quantity from here. In this example, we will look into the bus voltage,

rotor angle, and speed deviation of synchronous generator at bus 2.

11. To select bus voltage if you click on “Bus quantity”, you will see the following window:

12. When you will click “Select” as highlighted above, the following window will appear

Select bus-2 as shown above and press “OK”.

13. Now select voltage from the dropdown menu as highlighted below and click on “GO”.

If you want to look at other responses as available there, you can select them and finally

close the window. At this point you have selected the voltage response of bus-2.

14. Now in order to select the other quantities such as rotor angle speed deviation, you have

to go to step 10 and select “Machine quantities”. At this point, you will see the

following window:

15. Select bus -2 as shown in the following window and click on “OK”.

16. Now select the “Angle” from the dropdown menu as shown below and click on “GO”.

17. Now select the Speed from the dropdown menu as shown below and click on “GO”.

If you want to look at other responses as available there, you can select them and finally close

the window. At this point you have selected the rotor angle and speed deviation response of

synchronous generator at bus-2.

18. Now go to the Dynamics->Perform Simulation->Perform Simulation(start/run)

19. At this point the following window will appear:

Change the highlighted part as mention in the following step.

20. In the Channel output file box as highlighted above type GOP1 or any other name. In

Run to type 0 as shown below:

21. Now, press the Initialize button. In the output bar you will see the following

information:

If you see the message “Initial condition check O.K” as highlighted above, you may consider

that your system is good enough to run. Otherwise, there is something WRONG.

Please do not close the “Perform Dynamic Simulation” window.

22. Now In Run to type 1 or anytime up to which you want to run the system without any

fault and the click on Run as shown below:

Now the aim is to conduct fault analysis.

23. Now if you click on Disturbance, you will see the following window

From the above window you can select the type of faults that you want to apply. In this

example, a bus fault will be applied at bus-2. So please click on Bus fault.

24. After clicking on Bus fault, you will see the following window:

25. Now if you click on “Select”, the following window will appear

Select bus-2 as shown above and press “OK”.

26. Finally press “OK” on the following window:

27. Now go to “Perform Dynamic Simulation” window and change “Run to” as the

duration of the fault. In this example, a three-cycle fault is applied for which the duration

will be 0.06 s. Therefore, in “Perform Dynamic Simulation” window “Run to” will be

changed as1.06 as shown below:

Finally hit “Run”.

Now it is essential to clear the fault which is mentioned in the following step.

28. Now go to Disturbance, and click on “Clear fault” as shown below:

29. At this stage, you will see the following window:

30. Now click on “Go” which will clear the fault. Now go to “Perform Dynamic

Simulation” window and change “Run to” as long as you want to run the system. In this

example, the system is operated till 5 s. Therefore, in “Perform Dynamic Simulation”

window “Run to” will be changed as 5 as shown below:

31. Now hit “Run” and click on “Close” to close the window. So you have completed the

dynamic simulation. Now you need to look at the response which is discussed in the

following steps.

32. Open the GOP1.out file by CTRL+O and File type .out and select GOP1.out as

shown below:

33. Click on Plot Data tab. In the tree view on the LHS of the window, expand Channel

Files->GOP1 folder and drag one of the channels on the open plot window. For terminal

voltage:

34. You can create new plots or delete plots from the Edit menu items and drop different

channels and view these plots.

For rotor angle:

For Speed deviation:

In the lab, you have to do the same for IEEE 30-bus system.