Control of a 3-phase 4 wire grid connected converter with active power filter and var compensation functionality for nonlinear loads

This paper presents control of real power and reactive power together with active filter functionality of a grid connected voltage source converter for 3-phase, 4 wire system in order to eliminate harmonic currents associated with non-linear load in each phase. A classical instantaneous real and reactive power control method is used together with a harmonic elimination technique. A three-phase voltage source converter is used to control the reference current based on fixed hysteresis band current control. The active and reactive power are independently controlled whilst the grid current is compensated to be nearly sinusoidal waveform. The simulation results verify the correctness of operation for the proposed functions using MATLAB/Simulink.