Power related phenomena in three-phase unbalanced systems

The paper deals with the power properties of three-phase circuits with unbalanced loads supplied from a three-wire line. It discusses various definitions of the apparent power in such circuits and shows that they cannot be interpreted in terms of any physical phenomena. The paper shows that the unbalanced power does not occur as an effect of the power oscillations and explains why this power does occur. The paper presents a decomposition of the supply current into the active, reactive, and unbalanced currents and shows that this decomposition can be considered as a fundamental for the comprehension of the power phenomena in such circuits and for the power factor evaluation