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I got error :"Derivative is infinite or NaN" when i put my parameter in synchronous generator model.

0 votes
asked Apr 21, 2021 by Panudech Podee (14 points)

1 Answer

0 votes

The issue is that you have defined the Q axis damper leakage inductance (Llkq') as zero.  The model uses a 1/Llkq' factor internally, resulting in the infinite derivative you're observing.

As suggested in the past, if you don't have a Q axis damper winding then set Llkq'=inf and Rkq'=0.  This will eliminate the error message.

Note that because you have a very large resistance (1e10) across the breaker, you may notice some numerical issues in the voltage when the breaker is open.  I suggest you remove the large resistance and change the machine's Model parameter to "Stator VBR" or "Full VBR".

answered Apr 21, 2021 by Bryan Lieblick (1,941 points)
edited Apr 21, 2021 by Bryan Lieblick
thanks you so much ; )