Fluctuation of the supply voltage flicker
BSRIA Power quality guide (AG 2/2000) was written by C C Pearson and V Uthayanan and published by BSRIA in July 2000. It states:
Voltage fluctuations are systematic variations of the voltage envelope or a series of random voltage changes, within the normal voltage range of nominal ± 10%.
Loads which can exhibit continuous, rapid variations in the load current can cause voltage variations that are often referred to as flicker. The term flicker is derived from the impact of the voltage fluctuation on lamps such that they are perceived to flicker by the human eye. Voltage fluctuation is an electromagnetic phenomenon whilst flicker is an undesirable result of the voltage fluctuation in some loads.
The flicker signal is defined by its rms magnitude expressed as a percent of the fundamental. Typically, magnitudes as low as 0.5% can result in perceptible lamp flicker if the frequencies are in the range of 6-8 Hz.
--BSRIA
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