Developing an active filter based on least square method

Abstract

The paper first achieves the real frequency with the power system voltage by using a novel frequency measuring method that is based symmetry principles. Then, it is proposed to obtain the power system current with least square method. At last, the harmonic current is acquired as the load current minus calculated sinusoidal waveform and it is used as the output of an active filter. The numerical simulation shows the new method is effective.