Topological research and comparison of low harmonic input three-phase rectifier with passive auxiliary circuit

A novel passive correction approach is proposed in this paper. By adding a passive auxiliary circuit to the ac side of the rectifier with dc-side C filter, the input currents and power factor can be improved. According to distinctive configurations of the auxiliary circuits, eight low harmonic input rectifier topologies are derived. Three rectifier topologies with better comprehensive performance are deeply analyzed and compared in operation principle, auxiliary circuit design and characteristic discussion. Experimental results from the prototypes are shown to confirm the validity of the analysis and the feasibility of the proposed approach.