Two-stage reactive compensation in a three-phase four-wire systems at nonsinusoidal periodic waveforms

Abstract

The improvement of the power factor in three-phase, four-wire, stationary, unbalanced and linear loads, supplied from an ideal and symmetrical source at nonsinusoidal periodic waveforms, is the subject of this article. The case of an ideal source or a source that has a negligibly low internal impedance was considered. The analysis was based on the load current decomposition, according to the Current Physical Components (CPC) theory. The paper presents fundamentals of design of reactive compensators for compensation of the reactive and unbalanced currents of linear time invariant (LTI) loads supplied with nonsinusoidal voltage in four-wire systems. A reactive balancing compensator consists of two compensators working in a star and triangle configuration. The article presents the method of calculating the parameters of such a compensator using the CPC power theory. It was proved that the reactive and unbalanced components of current can be fully compensated in the reactive compensator also in the case of nonsinusoidal waveforms in power networks.