Identification of instantaneous current components in three-phase systems

The theory of electric power for three-phase systems has been based on both the instantaneous value concept and the average value concept (mainly developed in the frequency domain). In the former, two orthogonal current vectors have been considered as the suppliers of the active and reactive power components, which are transferred between source and load. In the latter, active, reactive, scattering, unbalanced, and nonlinear currents are identified as the suppliers of the corresponding power components. Under stationary and periodic conditions, the authors demonstrate the identification of instantaneous current components defined by both concepts. Balanced or unbalanced loads with sinusoidal or nonsinusoidal phase voltages are considered.