DC Link Active Power Filter for Three-Phase Diode Rectifier

In this paper, a dc link active power filter (APF) for three-phase diode rectifier is proposed. The proposed dc link APF, which is composed of two series-connected bidirectional boost converters, intends to eliminate the input current harmonics. It is paralleled at the dc link of the diode rectifier and is coupled to the ac input with three line-frequency switches. Compared with the full power processed power factor correction (PFC) solution, the dc link APF is partially power processed in that it only compensates for the harmonic current component at the dc link. Thus, it features with lower power processing. Moreover, it exhibits better total harmonic distortion of the ac line current when compared with the traditional ac side shunt APF. Voltage and current loop models are developed for average current control, and the selection of the current loop bandwidth is presented. Switching stresses of the ac APF, the dc link APF, and the six-switch PFC are also calculated and analyzed. Experimental and simulation results demonstrate the effectiveness of this dc link APF.