Reduction of Harmonics using PQ based Hysteresis Controlled Active Filter

A three-phase inverter-based Active Filter (AF) controlled by Instantaneous real and reactive power theory (PQ theory) based hysteresis and PI controllers are presented in this paper. An Inverter based AF is used to reduce the harmonics caused by non-linear loads in the source voltage and current by injecting the compensating currents. The hysteresis Controller generates the gate pulses required for the operation of AF. Instantaneous real and reactive power theory (PQ theory) monitors the active and reactive powers and generates the reference current accordingly. PI controller regulates the voltage of the DC link capacitor. The MATLAB Simulink model has been designed for the proposed approach and the THD is reduced significantly.