A Method Of Checking The Voltage Fluctuation And Flicker

The voltage fluctuation and flicker is a increasingly serious problem of power quality. The process of analysis of voltage fluctuation and flicker includes the extraction voltage envelope signal and frequency spectrum of signal envelope analysis.Considering that the existing methods for the detection of voltage fluctuation and flicker, calculating the amount is too large, and the ways of wave filtering is complex.With the development of the smart grid, the demand on the methods for checking the voltage fluctuation and flicker based on digital methods becomes more and more urgent. This article will introduce a way to check the voltage fluctuation and flickers based on synchronous detection and S-transform, which is based on the developed S-transform to analysis signal concluding frequent time and envelope. This method is based on matrix similarity algorithm with two signal matrix multiplying to find the synchronous time. At the same time, the flicker signal envelope can be checked with the two signal multiplying. Afterwards, on the base of the traditional disperse S-transform, a new method with variable step which is adapt to the Gauss window determined by the frequency is brought in, which is convenient and efficient. This method can ensure the frequency and the amplitude of the flicker, meanwhile, the time when the signal appear and disappear. It maintains the multiresolution of traditional S-transform and with the sampling theorem a lot of superfluous information is neglected, which makes a better instantaneity and speed making a contribution to digitization.