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pause psspy.run based on the status of a monitored variable (to simulate an SPS)

asked Feb 5 '19

Peter B gravatar image

updated Feb 5 '19

Hi there,

In PSS/E dynamics I want to model a Special Protection Scheme (SPS), that takes some action (e.g. tripping specific generators, lines or loads) based on the value of some other monitored parameter or parameters (e.g. voltage/frequency at a given bus, flow on particular lines etc).

To achieve this, I think I'll need to be able to monitor the relevant parameters (easily done), and then when they reach given value(s), pause the dynamic simulation (the part I don't know) and take whatever is action is relevant (via some python command - easy), and then set psspy.run going again.

psspy.run syntax is below. It will run until time tpause, which must be a real number. I don't know how to pause the simulation other than that.

psspy.run(option, tpause, nprt, nplt,crtplt)

Does anyone know if it's possible to pause a simulation based on a monitored variable criteria? I fear that if it can't be done my only option will be to write a bespoke dynamic model in Fortran.

P.S. I know about load trip relay models etc in PSS/E. They won't achieve what I'm trying to do, which is monitor element X trip element Y.

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answered Feb 6 '19

perolofl gravatar image

Only a dynamic model can pause an ongoing simulation so you have two options:

1) Write a dynamic model to stop the ongoing simulation.

2) Use a Python loop to advance the simulation in small steps with psspy.run, checking the monitored parameters and perform any necessary action in each loop.

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Thanks perolofl, I feared that would be the case. I thought of the loop solution as well, but I anticipate it will make my simulation very slow. I'll do some experimentation and see how I go. I may also see if I can take this opportunity to learn how to code my own dynamic model.

Peter B gravatar imagePeter B (Feb 6 '19)

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Asked: Feb 5 '19

Seen: 724 times

Last updated: Feb 06 '19