Voltage fluctuations and flicker

Voltage fluctuation and flicker are the percentage of the difference between the maximum and minimum values ​​of the voltage relative to the rated voltage when the voltage amplitude changes regularly within a certain range, or the voltage amplitude does not exceed 0.9 pu to 1.1 pu (standard value). A series of random changes. This voltage change is called flicker to express the visual effects of voltage fluctuations on the lamp. Therefore, the flicker is a measure of the degree of susceptibility to lamp flashes caused by voltage fluctuations at different frequencies and the degree of stimuli causing flicker. The voltage fluctuation value is a subjective feeling of the human eye to the light flash.

The flicker limit caused by the user's load is based on the size of the user's load, the ratio of the protocol's power consumption to the power supply capacity and the system's voltage level. Percentage of the allowable voltage fluctuation of the public power supply point of the power system caused by the impact load. Divided into three levels for different specifications and restrictions.

(1) 10kV and below is 2.5

(2) 35~110kV is 2.0

(3) 220kV and above is 1.6

GB12326-2000 "Voltage Allowable Fluctuation and Flicker" specifies the flicker limit values ​​for each level of voltage. It applies to the rapid change of the voltage of the common connection point caused by the fluctuating load and may cause people to feel the light flashing. Occasions.