A Voltage Fluctuation and Flicker Monitoring System Based on Wavelet Transform

The voltage fluctuation and flicker monitoring system based on Wavelet Transform was developed by using the virtual instrument technology. The system consists of sensors, signal conditioning circuits, data acquisitions and computers. In the system, the arithmetic model of voltage fluctuation and flicker was established. This paper proposes a method of monitoring and analyzing voltage fluctuation and flicker based on the wavelet transform. In the system, the wavelet transform was applied to virtual instrument by using the MATLAB script node in LabVIEW, in which the signals were divided into multi-frequency bands according to the voltage flicker signal character, the feature of the flicker was extracted, frequency and amplitude of voltage fluctuation signal was gained, the moment at which voltage flicker occurs was detected.The evaluation indices of short-term flicker severity Pst are obtained by using statistic sorting algorithms.