Practical design of a control strategy based in current and voltage detection for hybrid power filters

The configuration of a series active power filter (APF) and a parallel passive filter (PPF) has proven to be an efficient system for nonlinear load compensation. Different compensation strategies have been proposed to control the series APF. The most effective strategy determines the APF reference voltage as addition of two terms. The first one is proportional to source current harmonics and the second one is opposite to the load voltage harmonics. The control strategy has been analyzed from the state model of the single phase equivalent circuit. The resulting model analysis provides the information needed to establish design criteria for the control strategy, both in terms of harmonic filtering and the system stability. The design criteria have been applied to load type of current source harmonics (CSH). Finally, results of an experimental prototype developed for this purpose allowed the proposed analysis to be verified. The filtering equipment has been contrasted in two different situations: sinusoidal supply voltages and distorted supply voltages.