perolofl's profile - activity

Motor starting can be simulated in PSSE. See Program Application Guide II, Chapter 21.2.4.

It is very advanced to write ypur own generator model!

You can use inibrn and loop through all lines with nxtbrn, check the sign of P and sum all injections to the bus.

The total power flow into a bus is zero if we neglect the small mismatch. API brnflow returns the flow on an individual branch.

It is a copy and paste error in the manual. IC must be 101 and IT must be 1.

API brnflo returns the complex power for a branch.

The error is caused by no data in memory. The saved case is not opened. Perform psspy.case() first.

Current magnitude and angle can be calculated from the power injection (P+jQ) for each connected object (branch, transformer, load, shunt, generator, etc).

You have to find out yourself what is causing the instability. As I understand the original IEEE 14-bus system has 5 generators an no condensers.

The condensers supply inertia and short circuit power during the simulation. Obviously, the system becomes unstable without them.

Perform a simulation with the condensers and plot P & Q to see their support to the system.

The easiest is to use API treedat, which returns a lot of information in a dictionary. The following will return a list with a sublist with bus numbers in every found island.

treeobj = psspy.treedat(999)
islandbuses = treeobj['island_busnum']

For eaxemple, with three islands the list may look like this:

[[101], [102], [201, 202, 203, 204, 205, 206, 211]]

This can be merged into one single list with:

islandbuslist = [j for i in islandbuses for j in i]

Now the list is:

[101, 102, 201, 202, 203, 204, 205, 206, 211]

Everything in a single line:

islandbuslist = [j for i in psspy.treedat(999)['island_busnum'] for j in i]

----------
 ----------------------------- MACHINE INITIAL CONDITIONS -----------------------------
   BUS# X-- NAME --X BASKV ID  ETERM   EFD    POWER    VARS   P.F.      ANGLE   ID     IQ
      1 1                    0.6900 1  1.0204 0.0000  100.01    0.00   1.0000   7.79 0.0000 0.9801
      4 4                    220.00 1  1.0200 1.0376  -99.05   13.56  -0.9908  -5.32 0.2223-0.9546

INITIAL CONDITIONS CHECK O.K.

That's what I got after initializing. Both SBASE and MBASE are 100MVA, you can see that POWER=IQxETERM and VARS=IDxETERM. Why is that? Don't we usually use d for Pe and q for Qe?

It is normally very easy to start PSSE-35 from python. It is no longer needed to add libraries to the system path. This will start the newest installation of PSSE-35:

import psse35
import psspy
psspy.psseinit()

You are using the old API (DCLF) with the arguments for the new API (DCLF_2). It should be:

psspy.dclf_2(1, 1, [1,0,1,2,1,1],[0,0,0], '1')

Yes, use VAR(L+3) = STATE(IVAL+1)

It is better to show the load flow data for the generator and the dynamic data for CBEST.

Switch on a load during the simulation.

Yes, you can use VAR(L+1) = IERR

Put the first VAR of the model into a channel.

See post "Monitoring VAR and STATES - Dyn "

Don't name your model REGCAU1! It must have a unique name.

A wind generator model is a current injection model (IT=1) and is called in both TBLCNC and TBLCNT. The subroutine REG is called in TBLCNC and the subroutine TEG is called by PSSE in TBLCNT.

Your model needs an entry point for subroutine TEG so PSSE can call it in TBLCNT.

Read about Coordinated call in POM.

See also post "Question about coordinated call models".

Variable IVAL will contain the index of the first STATE for the wind generator model at bus 2, machine 1.

The third VAR should be VAR(L+2) = STATE(IVAL)

Variable IERR is zero when the call is succesful. It is wrong to assign VAR(L+3) = VAR(IERR), since VAR array doesn't have index 0. Remove the statement for VAR(L+3).

When I use a call like WINDMIND, how could I get and use the output value?

In API.pdf, it shows the Fortran syntax:CALL WINDMIND(IBUS, ID, STRING1, STRING2, IVAL, IERR)

So, I write:

CALL WINDMIND(2,'1','WGEN','STATE',IVAL,IERR)

In order to get the output, IVAL, I write the below code in my understanding:

VAR(L)=IVAL
VAR(L+1)=IERR
VAR(L+2)=VAR(IVAL)
VAR(L+3)=VAR(IERR)

I put all these codes in a GUST model ,MODE 3, and in .dyr I write

2 'USRMDL' 1 'API' 106 0 0 0 0 4

All other models in .dyr are offical models like REECAU1...

However, when I start dynamic simulation, all the VARs are 0.

How to solve this problem?

Thanks, very nice solution!

The magnetizing admittance is returned as a complex value. Hence, API ATRNCPLX shall be used. See example below:

ierr, [ymag] = psspy.atrncplx(-1,  entry=1, string=['YMAG'])
for c in ymag:
    print(c.real,c.imag)

Here list ymag contains the complex value of (G,B) in pu system base.

No, it is not possible!

The API will only change the value in the working files. You have to save current data to a raw data file with API RAWD_2.

One way may be to open both files with dyntools and compare the channel values.

Do you mean result files from dynamic simulations (.out) or any other kind of output from PSSE?

Use API psspy.abrnint. For example:

ierr, [ibl,jbl] = psspy.abrnint(-1,  flag=4, string=['FROMNUMBER','TONUMBER'])

will return all from bus numbers in list ibl and all to bus numbers in list jbl for all branches and two-winding transformers.

I don't understand. What do you mean with "see results when open out file"?

Have you tried with another snapshot?

The problem is not clear. Are you plotting an out-file with PlotBook?

First of all I strongly recommend to use Python instead of response file for automation of PSSE.

In PSSE all faults are entered as shunts (G+jB) in MVA. For example a solid three phase fault may be entered as a large inductive shunt (G=0, B=-2e9). In the BAT command VALUES(1) )= G and VALUES(2) = B.

In your case:

BAT_DIST_BUS_FAULT IBUS 1 BASEKV  0 -2e9

BASEKV is only needed if UNITS = 2 or 3 and there is no bus base voltage entered for IBUS in the saved case. Normally BASEKV can be entered as 0.0, i.e.:

BAT_DIST_BUS_FAULT IBUS 1  0  0 -2e9

for a solid three phase fault.

I believe it is a user model:

IBUS 'USRMDL' ID 'REGCBU1' 101 1 2 7 5 8 ICON(M) to ICON(M+1) CON(J) to CON(J+6) /

Constants emax and emin are just limitations on the input signal to the PI Q-controller. Enter large positive and negative numbers to ignore the limitation.

Can you show the data for the plant?

It works fine for me. Are you sure you haven't modified the source file? Do you find ENCOD in the code?

When machines with missing generator models are gnetted automatically at initialisation Pgen is modelled as constant current load and Qgen is modelled as contant impedance load. Both Pload and Qload are zero!

In the example below I have deleted the generator model for machine at bus 102 in savnw network. After initialisation, the machine is gnetted and replaced with a load:

The load data are shown below:

You have to buy a real license!

Then you can only use models with a maximum of 300 ICONS.

You probably has to compile module ENCOD before compiling any code refering to ENCOD.

Well, Moji wrote that he is not talking about channels...

What is the problem with to just write a bus location file and let python read the file and get the bus numbers?

Switched shunts models are changed in rev 35 since multiple switched shunts are allowed at a bus.

The subroutine call is now SUBROUTINE XXXXXX(ISW,ISLOT), where ISW is the internal number of the switched shunt.

Since the switched shunt index (ISW) is an input into the model, any references to NSWICH (which was used to obtain the switched shunt index earlier) need to be removed.

See Chapter " Changes in Dynamics when Modeling Multiple Switched Shunts" in rev 35 Release Notes.

Triangularized Y matrix network solution.

It is better to use model TIOCR1 to trip the line automatically at overcurrent.

Do you have a real license or a free xplorer license? How many ICONs in your snapshot?

Your dynamic models use more ICONS than allowed in your PSSE installation.

Use activity SIZE to see the number of ICONs used and allowed.

Change to a larger PSSE size or reduce the number of models using ICONs.

See post "Intel Runtime Libraries not found - PSSE Installation"

You can have two transmission lines between infinite bus and POI. Simulate trip of one branch. The new load flow will change the bus angle at POI.

Do not use playback model in this simulation, use GENCLS instead.

EDIT:

A better alternative is to have a transformer between infinite bus and POI. Change the transformer phase shift during simulation to emulate a voltage angle phase shift. In this way you can select the wanted angle shift, e.g. 5 deg, 10 deg , 15 deg etc.