周军,何振梁,李曙光.小角度法结合复合形态滤波器的单相电压跌落检测方法[J].电测与仪表,2020,57(2):116-121. Zhou Jun,He Zhenliang,Li Shuguang.Single phase voltage sag detection method based on small angle method combined with complex morphological filter[J].Electrical Measurement & Instrumentation,2020,57(2):116-121.
Single phase voltage sag detection method based on small angle method combined with complex morphological filter
Aiming at the problems of frequent voltage sags and the inaccuracy and rapidity of traditional Voltage Sags Detection methods, a fast single-phase voltage sags detection method based on delay small angle method and composite morphological filter is proposed. The principle of the small angle delay method and the composite morphological filter are discussed in detail. The method uses the composite morphological filter to filter the power signal for the first time, constructs the virtual three-phase voltage by the small angle delay, transforms the three-phase voltage by Park and filters the residual harmonic components by the linear morphological filter. The filtering effect of the composite morphological filter is simulated and analyzed. The voltage sag waveforms disturbed by complex noises and harmonics are simulated and tested. The actual hardware model of voltage sag is built and the algorithm is validated again by the collected data. The results show that the method can detect the onset time, depth and phase of voltage sag quickly and accurately.