A detailed instantaneous harmonic and reactive compensation analysis of three-phase AC/DC converters, in abc and αβ coordinates

This paper presents a digital simulation of an active filter, in which the instantaneous harmonic and reactive compensating currents are desegregated in their different αβ space-trajectories, and in their time-domain waveforms of both the abc and the αβ system of coordinates. Departing from Akagi´s generalized instantaneous reactive power theory, a complete analysis is presented, in which the counterharmonic compensating current injected to the coupling point of the AC mains feeding a six-pulse-controlled three phase AC/DC power converter is desegregated in its three components, namely: (a) fundamental reactive current; (b) oscillating harmonic reactive current; and (c) oscillating harmonic active current. It is demonstrated, in a selected number of abc and αβ oscillograms and current-space-trajectories that the active filter can compensate either separately or jointly the above mentioned currents.