Light flicker caused by interharmonics and interharmonic-flicker curves of lamps

Flickers and interharmonics have an inherent relationship. The aim of the paper is to describe procedures for systematical determination of immunityof lamps to supply voltage variations caused by interharmonics. The curve of lamp immunity ispresented as an interharmonic magnitude versus interharmonic frequency curve and is called interharmonic-flicker curve. The interharmonic-flicker curves of lamps are determined by utilizing a modified concept formeasurement of a lamp gain factor in frequency domain and by utilizing the published limits on voltage flicker. Another described method for establishing the interharmonic-flicker curves of lamps is the method based on measuring the luminous flux flicker curve which is defined by utilizing the published limits on voltage flicker as well. Further a complex measured data file of interharmonic-flicker curves in various combinations of fluorescent lamps (FLs)and ballasts are pointed. Measured and compared combinations include various types of fluorescent lamps, various wattages, modes of operation of the ballast and its specific designs and dimensioning of circuit elements etc. Finally, determined interharmonic-flicker curves of chosen lamps are used for proposal approach how to revise the compatibility level for interharmonic voltages relating to flicker.