Implementation of Instantaneous Reactive Power Theory for Current Harmonic Reduction and Reactive Power Compensation in Three Phase Four Wire Power System

Most of the pollution issues created in power systems are due to the non-linear characteristics and fast switching of power electronic equipment. Power quality issues are becoming stronger because sensitive equipment will be more sensitive for market competition reasons, equipment will continue polluting the system more and more due to cost increase caused by the built-in compensation and sometimes for the lack of enforced regulations. In this paper instantaneous reactive power theory (IRP theory) is proposed for calculating the reference compensating currents required to inject into the network at the connected point of non-linear load. Switching scheme of compensator is provided by comparing the reference compensating currents obtained from IRP theory and compensator currents. Thus IRP theory is used to identify the amount of compensating current injected into the network to compensate the reactive power required by non-linear loads and to bring the source current waveform as sinusoidal. Simulations for a three phase three wire system and three phase four wire system with a shunt active power filter have been carried out for current harmonic reduction and reactive power compensation. Thus power factor has been improved by attaining source voltage and source current in phase.