AC- and DC-Power Quality improvement of diode rectifiers due to parallel-series active filtering

This paper discusses a parallel-series active power filter (APF) for a three-phase diode rectifier. The proposed APF can improve the ac-side power quality at the point of common coupling and additionally the dc-side power quality at the rectifier. The aim of investigations is to reduce the total effort of filtering. A new control strategy by the series APF that generates a constant dc-current without any dc-side choke, is shown. This control strategy leads to a smaller dc-side capacitor and reduces the size of the shunt APF. Simulations results are shown.