New extraction method for active, reactive and individual harmonic components from distorted current signal

Abstract

Quality problems encountered in power systems usually originate from reactive and harmonic current components drawn by non-linear loads. Therefore the extraction of reactive and harmonic current components from distorted current waveform is a vital issue in the works aiming to monitor and eliminate power quality problems. In this study, a new method that provides the extraction of active, reactive and harmonic current components from distorted current is presented. The method has been based on the differential equation of the single-phase source-load system. The proposed method performs computations by using a sliding sampling window that has a width of half of the fundamental cycle. Immunity to noise, being less affected from frequency deviations and being not influenced from dc component that may exist in load currents are some other advantages of the proposed method. The method has been analysed and compared to two commonly used methods, namely discrete Fourier transform (DFT) and dq, by using a series of simulations that have been executed in Matlab/Simulink environment. Simulation results demonstrated the effectiveness of the proposed method.