Voltage Flicker Monitoring Based on Virtual Instrument and Wavelet Packet Transform

This paper proposes a new method of monitoring and analyzing voltage flicker based on wavelet packet transform and virtual instrument, and establishes an arithmetic model of the system. First, through the wavelet package transform, we can extract the amplitude modulation waveform, get the accurate time when the voltage flicker occurs and stops, and count the frequency and amplitude of voltage fluctuation. Then, the sensation level weighted filter, square multiplier and first order low pass filter can be designed. Finally, the evaluation indices of short-term flicker severity can be obtained by using statistic sorting algorithms. Experiment results show that this method is very applicable for the detection of non-stationary voltage fluctuating and flicker signals.