Detection of voltage flicker based on blind source separation of minimum mutual information

To measure the parameters of voltage flicker accurately,blind source separation algorithm is presented based on the criterion of minimum mutual information.Taking the mixed signal containing voltage flicker as blind signal,the paper samples the order of mixed signals and delays them a number of points,and constructs the input signal matrix.The voltage flicker envelope curve is separated from mixed signal with Fast-ICA algorithm based on blind source separation of minimum mutual information.Then frequency and amplitude of the envelope curve are calculated and short-term flicker value is acquired.An experimental circuit containing signal generation circuit,power amplifier circuit and sampling circuit is designed.Experiment results show that the method is more effective in stationary and instantaneous voltage flicker detection.The method is better than conventional FFT algorithm when envelope curve contains inter-harmonics.