I have seen that when initializing a dynamic simulation, sometimes the state variables are not always O.K., so I have been told I can try to Initialize again (STRT function), in an attempt to iteratively find the message Initial Conditions O.K.
Is this really an industry practice? What usually is the source of not being able to initialize on the first STRT function?
Thanks!
In my opinion is is a bad practice to initialise several times to get rid of initial condition suspect. This will lead to a different starting point for the voltages, currents and flows than the load flow solution. Also running to x seconds will lead to a different starting point.
Instead, the root of the problem should be corrected. See post Question for initial condition suspect.
Initial condition suspect is caused be at least one dynamic model with limitations that will prevent the model to be initialised to the same conditions as in the solved load flow. It may be caused by e.g. an exciter model, governor model, renewable model, SWS model, FACTS model, HDDC model, etc. Problem with one model may cause hundreds of DSTATE problems in a large part of the network. Look for the models with large DSTATEs.
For reference, search the forum for "initial condition suspect". If the network and dyr data does not change, multiple STRT would not be different from the first STRT outcome. Having state variables not OK, one trick is to run dynamics for x-seconds and test the outfile for max. deviations. Keep/save the case and snap file for the scenario with acceptable low deviations.
A better approach is to resolve the states that are listed in the "initial condition suspect" table inside the log following the STRT activity. exa.: if the "initial condition suspect" table list a state var belonging to a governor model, check if the corresponding generator in the load flow may need to adjust its power output or a dyr value in the governor model can be tuned/revised/changed.
Asked: Jan 11 '5
Seen: 202 times
Last updated: Jan 13
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Thanks for your answer. I reached out directly to SIEMENS as well, and their answer goes as follows: If the STRT (first time you do STRT) produces initial conditions suspect (ICS), you should not do multiple STRT to get rid of the ICS as this only masks the cause of the ICS.