A new method for instantaneous reactive power compensation in three-phase four-wire systems

This paper proposes a novel method to generate the current reference for a parallel active power filter that does not need energy storage elements. The method compensates for the reactive power and eliminates the neutral current in unbalanced three-phase four-wire systems (sinusoidal or nonsinusoidal) with or without zero-sequence components in the currents and /or voltages. In contrast with existing methods, no coordinate transformation is used, assuring a simple controller design and implementation. Simulation and experimental results are provided to validate the proposed method.