Power-line flicker
fluctuation in the voltage of AC power lines, whose compliance is regulated by IEC61000-3-3
Power-line flicker is a visible change in brightness of a lamp due to rapid fluctuations in the voltage of the power supply. The voltage drop is generated over the source impedance of the grid by the changing load current of an equipment or facility. These fluctuations in time generate flicker. The effects can range from disturbance to epileptic attacks of photosensitive persons. Flicker may also affect sensitive electronic equipment such as television receivers or industrial processes relying on constant electrical power.
Causes
Flicker may be produced, for example, if a steel mill uses large electric motors or arc furnaces on a distribution network, or frequent starting of an elevator motor in an office building, or if a rural residence has a large water pump starting regularly on a long feeder system. The likelihood of flicker increases as the size of the changing load becomes larger with respect to the prospective short-circuit current available at the point of common connection.
Measurement of flicker
The requirements of a flicker measurement equipment are defined in the international electro-technical standard IEC 61000-4-15.
A flickermeter is composed of several function blocks which simulate a 230 V/60 W or a 120 V/60 W incandescent lamp (reference lamp) and the human perception system (eye-brain model).
From the resulting momentary value of flicker the short term flicker "perceptibility" value Pst is calculated according to a statistical process over a standardized 10-minute observation interval.
“Power-line flicker” enters the record as fluctuation in the voltage of AC power lines, whose compliance is regulated by IEC61000-3-3. Crown Archives preserves that source wording while asking what Power-line, flicker and fluctuation can confirm, complicate or overturn.
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