Different Approaches Assesment in Active Power Filter Compensation

In this paper, the five main formulations of the instantaneous reactive power theory have been chosen to study a nonlinear load compensation. They are p-q original theory, d-q transformation, modified or cross product formulation, p-q-r reference frame and vectorial theory. The obtention of the compensation current according to each formulation has been established. Next, the behavior of an active power filter (APF) implemented with those different control algorithms have been studied. The APF control strategies have been implemented in an experimental platform constituted by a 20 kVA power inverter and a 400 MHz digital signal processing (DSP) controller board. Results got from an unbalanced and non-sinusoidal three-phase four-wire system have been compared. The final analysis shows that, in general, the five theories present a different behavior, depending on the supply voltage, respect to the distortion. However, all of them widely decrease the waveforms distortion. Moreover, a more general compensation objective is possible. It obtains balanced and sinusoidal source current in any conditions of supply voltage