Selective Shunt Active Power Compensator in Four Wire Electrical Systems Using Symmetrical Components

Abstract

Abstract This article analyzes the inefficiencies present in four wire electrical systems where linear unbalanced loads are connected. The new reference currents are proposed for the selective compensation of the inefficiencies using a three-legs shunt active power converter. The positive-, negative- and zero-sequence components of voltages and currents in load terminals determine the compensating currents that cancel the inefficient power flows. A new method for the control of the voltage unbalances in the split DC bus is proposed. Simulation and experimental results demonstrate how the proposed compensating currents improve efficiency in systems with voltage asymmetries and current unbalances.