Interharmonic-Flicker Curves

Flickers and interharmonics have an inherent relationship. The magnitude of a voltage can fluctuate if it contains interharmonics. This paper proposes a limit for interharmonics by utilizing the published limits on voltage flicker. The limit is presented as an interharmonic-magnitude versus interharmonic- frequency curve and is called interharmonic-flicker curve. The interharmonic-flicker curves based on the rms and peak magnitude fluctuations and on the IEC flickermeter are derived. A systematic method to derive limits for interharmonics from the flicker limits is presented. The paper also reveals that the IEC flickermeter needs improvement when dealing with interharmonic- caused flickers. Potential applications of the proposed interharmonic-flicker curves include the designing and evaluation of mitigation measures to reduce the flicker impact of interharmonic producing sources.