Power theory evaluation for the control of an active power filter

Various power theories have been developed to define power under nonsinusoidal current conditions. After widespread use of Bundeau's concept of reactive power in the frequency domain, for almost 60 years, its inability to be used in compensating devices has led to the revival and implementation of time domain based techniques for power compensation. A comparison of the time-domain correlation techniques derived by Enslin, the instantaneous reactive power theory (IRPT) introduced by Akagi and the synchronous reference frame (SFR) suggested by Divan is carried out and evaluated under nonsinusoidal conditions and voltage unbalance. The level of compensation for distortion and reactive power are compared and practical implications of the implementation of each theory in a digital signal processor (DSP) are discussed. Simulated and experimental results of a 100 kVA inverter used as an active power filter (APF) are presented.