LAUSR

This study presents a model-based controller for a hybrid power filter (HPF) to reduce the current harmonic distortion in a three-phase system for a general operation case considering unbalanced and distorted source voltages and load currents. The HPF comprises an active power filter (APF) grid connected by means of an LC passive filter. This topology is aimed to reduce the current rating handled by the APF, representing a cost effective solution. The controller design is split into two stages, a first one to control the fundamental component of the system dynamics, and to regulate the DC voltage; and a second stage to compensate the harmonic distortion caused by a non-linear load. For this, the harmonic compensation scheme forces the injection of the required harmonic current to the point of common coupling. The proposed scheme keeps the very familiar proportional-resonant control structure. The compensation of the load reactive current is left to the passive filter. Experimental and simulation results are presented to exhibit the benefits of the proposed control solution.