A novel current detection algorithm for shunt active power filters in harmonic elimination, reactive power compensation and three-phase balancing

A novel current detection algorithm based on time domain approach for three-phase shunt active power filters (APF) to eliminate harmonics, and/or correct power factor, and/or balance asymmetrical loads are analyzed in this paper. First, a basic overview and evaluation of the performance of three existing current detection algorithms for active power filters is presented. According to different complicated power quality issues and various compensation purposes, a novel current detection algorithm is then proposed. Comparing with existing algorithms, this algorithm has shorter time delay and clearer physical meaning. Different compensating current references can thus be accurately and easily obtained by adopting the proposed algorithm. It ensures that a shunt APF can very well achieve different compensation purposes. Moreover, it is very easy to implement this algorithm in a digital signal processor (DSP). Simulation results obtained with Matlab and testing results on an experimental shunt APF are presented to validate the proposed algorithm.