DSP-BASED IMPLEMENTATION OF AN IMPROVED CONTROL ALGORITHM OF A THREE-PHASE ACTIVE FILTER FOR COMPENSATION OF UNBALANCED NON-LINEAR LOADS

摘要

This paper deals with an implementation of a new control algorithm for a three-phase active filter (AF) to eliminate harmonics, compensate reactive power and to balance unbalanced nonlinear loads. An insulated-gate-bipolar transistor (IGBT)-based current-controlled pulse-width modulated (PWM) voltage-source inverter (VSI) with a DC-bus capacitor is used as an AF. The reference supply currents are derived in phase with supply voltages using a sliding mode controller (smc)over DC-bus voltage of he AF.A digital signal processor (DSP) is used to implement the control algorithm of the AF. An indirect PWM current control over the reference and sensed supply currents is implemented for generating the gate signals for IGBT of the AF. Test results of the proposed AF are given to demonstrate the harmonic elimination, reactive power compensation and load-balancing capabilities of the AF.