Power Properties of Four-Wire Systems at Nonsinusoidal Supply Voltage

Powers of three-phase aggregates of single-phase static linear loads supplied with a nonsinusoidal voltage are the subject of this paper. It is demonstrated in this paper that the supply current of such systems with a nonsinusoidal voltage can be decomposed into six mutually orthogonal components associated with distinctive physical phenomena in the load, two of which do not exist at a sinusoidal voltage. Such decomposition enables evaluation of contribution of these phenomena to the supply-current rms value increase and the power factor decline. A power equation and definitions of powers in such systems in the presence of voltage harmonics are proposed. This paper shows that all powers can be expressed in terms of load parameters, which can be identified by a measurement at the load terminals.