APF for Mitigation of Current Harmonics with p-q and Id-Iq Control Strategies using PI Controller

Abstract

Due to a large amount of non-linear power electronic equipments, impact and fluctuating loads (such as that of arc furnace, heavy merchant mill and electric locomotive, etc), problems of power quality have become more and more serious with each passing day, as a result Active power filter (APF) gains much more attention due to excellent harmonic compensation. But still the performance of the active filter seems to be in contradictions with different control strategies. This paper presents detailed analysis to compare and elevate the performance of two control strategies for extracting reference currents of shunt active filters under balanced, un-balanced and non-sinusoidal conditions by using PI controller. The well known methods, instantaneous real active and reactive power control strategy (p-q) and active and reactive current control strategy (i_d-i_q) are two control strategies which are extensively used in active filters. Extensive Simulations are carried out with PI controller for both p-q and I_d-I_q control strategies for different voltage conditions and adequate results were presented. Simulation results validate the superior performance of active and reactive current control strategy (i_d – i_q) with PI controller over active and reactive power control strategy (p-q) with PI controller.