Real time digital simulation of shunt active filter for mitigation of current harmonics with P-Q theory

Abstract

The main objective of this paper is to develop PI and Fuzzy logic controllers to analyze the performance of instantaneous active and reactive power (p-q) control strategy for extracting reference currents of shunt active filters under balanced, un-balanced and balanced non-sinusoidal conditions. When the supply voltages are balanced and sinusoidal, then all controllers converge to the same compensation characteristics. However, when the supply voltages are distorted and/or un-balanced sinusoidal, these control strategies result in different degrees of compensation in harmonics. The p-q control strategy with PI controller is unable to yield an adequate solution when source voltages are not ideal. Extensive simulations were carried out; simulations were performed with balance, unbalanced and non sinusoidal conditions. Simulation results validate the dynamic behavior of Fuzzy logic controller over PI controller. The 3-ph 4-wire shunt active filter system is also implemented on a real time digital simulator (RTDS Hardware) to further verify its effectiveness. The detailed simulation and RTDS Hardware results are included. Key words: Harmonic compensation, shunt active filter (SAF), P-Q control strategy, PI controller, fuzzy controller, RTDS hardware.