Harmonic modeling and simulation considerations for interharmonic limits in the revised IEEE Standard 519-1992

One of the major differences in the revised IEEE Std 519 and the 1992 version will be the inclusion of interharmonic limits. These limits are likely be based on voltage fluctuation considerations below the second harmonic and are consistent with even-order harmonics for frequencies above the second harmonic. Much is known about equipment modeling for frequencies above the power frequency, but significant work is needed to address modeling and simulation issues near or below the power frequency. Because voltage fluctuations can become problematic at very´ low levels, it is necessary to obtain greater accuracy in results than is often the case in harmonic studies. There is, therefore, a clear need for improvement in models and simulation techniques for lower frequencies.