Evaluating correlations between interharmonics and voltage fluctuations

Amplitude modulation is a well-known cause of voltage fluctuations resulting in light flicker. Amplitude modulation can be more generally quanlified in terms of interharmonics. As the use of 60 W incandescent lamps declines, the need increases to broaden voltage fluctuation quantification beyond light flicker. If interharmonic measurements could be correlated to currently accepted flicker severity measurements, the effort to make inter-harmonic measurements the grounds of general voltage fluctuation measurement could be justified. This relationship between interharmonics and classic light flicker has been explored in this paper. The recommendations in IEC 61000-4-7 and 61000-4-15 for measuring interharmonics and short-term flicker severity, respectively, were followed. Interharmonic measurements were accumulated over 10 minutes in order for them to be easily compared to the short-term flicker measurements.