Hi, I tried changing the limits to the ones you recommended above, the result was that the calculated rms value was now higher than the highest component from the FFT analysis. However the value was over 100V higher, than the value I got from using the waveform points in the equation for rms, in an excel spreadsheet. I tried altering the limit values in the cycle average VI to various values, but this had no effect.
In answer to your last question, we are trying to analyze the stator winding voltage from a turbo generator and thus calulate the Telephone Harmonic Factor (THF) or Telephone Influence Factor (TIF), depending on the frequency of the machine. And the rms voltage value is crucial in these calculations.
