Harmonic Study with ETAP

[niulun]

Hi

I'm trying to perform an Harmonic Study with ETAP 5.03, but an error occour durig the preliminary load flow.
In the Info page of the Harmonic Analisys Study Editor I set the following values:

Max. iteration: 6000
Precision: 0.000001
Accel. Factor: 1.45

Error message: Load Flow calculation results indicate large power mismatch (>1MW) at some busses.


I don't understand exacly what it means and moreover during load flow analisys no busses have power mismach.


Does enyone can help me?

 

[electricpete]

Just a GUESS - maybe the solution hasn't converged yet... try bumping up your max interations?

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[dpc]

If a normal power flow run converges, but the harmonic analysis does not, I'd double-check any data you have entered related to non-linear loads. Make sure you have everything in the correct units and that everything makes sense.

If you don't find anything, try "turning off" non-linear loads to see if you can locate whatever is causing the model to blow up.

Power flow algorithms can be sensitive to small changes in transformer taps, per unit voltages, etc.

Try getting back to a configuration that does converge, then make small changes.