A time domain based flickermeter with response to high frequency interharmonics

Fluctuation of a supply voltage is primary viewed, for historical reason, as voltage amplitude modulation (AM) and the response of UIE/IEC flickermeter, which is based on incandescent bulb - human eye - brain scheme, is designed exactly for such fluctuation. From another point of view, a voltage magnitude fluctuation could be introduced also by subharmonic and/or interharmonic components superimposed on a voltage waveform. The boundary interharmonic frequency of a voltage AM is approx. double of fundamental system frequency (f₁) and for this reason the response of the standard UIE/IEC flickermeter to interharmonic voltages is also up to 2* f₁. Nevertheless, high frequency voltage interharmonics (over 100 Hz) are likewise able to produce light flicker. That is valid for all lamps, except incandescent. And the instrument is expected to properly work and measure also the effects of these interharmonics. The paper discusses the realization of flickermeter in time domain for frequency range up to 3 kHz in Matlab-Simulink environment. The used modifications are based on the analysis of voltage fluctuation caused by integer and non-integer harmonics in range of DC to 3 kHz, on utilization of the measured interharmonic-flicker curves of lamps, and are performed in the block 1 to block 4 of the standard flickermeter scheme.