Study on an Improved Single-phase Harmonic Current Detection Algorithm

Bases on present harmonic detection algorithms, single-phase load current is decomposed and a novel single-phase current detection algorithm, which is simple, reliable, response quickly and favors the hardware realization, is proposed, in order to solve complexity of algorithm and slow response of common used single-phase harmonic detection methods. Meanwhile, as the method need to use low pass filter, an improved method is is analysed. By increasing time delay unit, the effect of 2nd harmonic was eliminated, and the cut-off frequency of the low-pass filter was increased without adding the filter order. The response time of improved detection was shorten about half period. Correctness and validity of the proposed method were verified through simulating and experiment.