Flicker Dependency on Voltage Fluctuation at Frequencies Greater Than Power Frequency

Voltage fluctuation of the power supply in a circuit containing light sources can cause flicker. The relationship between voltage fluctuation and flicker is quite complex. In this paper, the occurrence of flicker for voltage fluctuations with frequencies higher than the power frequency is investigated on the basis of laboratory measurements. Eight light sources have been used in the study – three incandescent bulbs and five low-power LED lamps. For clipped cosine voltage, flicker was confirmed to occur for frequencies up to seven times the power frequency, namely 350 Hz. It has been observed that LED lamps may be more susceptible to voltage fluctuation than incandescent bulbs, especially at higher fluctuation frequencies.