Algorithm Analysis on Measuring the Begin-end Time of Voltage Sag Based on Biorthogonal Wavelet

With the development of economy, technology and society, the requirements of power quality improved gradually. To improve power quality should obtain power informations first, and the direct approach of obtaining informations is detecting the power quality. It is quite effective to detect and analyze the singularity and singularity positions of signals by using wavelet transform, because wavelet transform has space localized properties. This paper firstly expounds the principle of wavelet singularity detection and the relationships between signal singularity and maximal modulus of wavelet transform. Secondly, the algorithm on measuring the begin-end time of voltage sag in the electrical distribution system is analyzed by using binary wavelet. Finally, this algorithm is simulated by MATLAB. Experimental results show that this method can detect the begin-end time of disturbance signal accurately