Soft-switching three-phase matrix based isolated AC-DC converter for DC distribution system

In this paper, a novel three-phase matrix based isolated AC-DC converter is proposed for DC distribution system. The circuit is derived from boost converter based matrix PWM rectifier by only adding a small commutation capacitor and inductor. Compare to traditional power factor correction rectifier plus DC/DC two-stage configuration, the proposed converter has higher efficiency and power density. Soft-switching can be realized for all switches and the intermediate DC capacitor is eliminated in the proposed topology. Also, compared to the buck-derived single stage solution, it requires smaller size EMI filter in the AC input stage. Furthermore, a novel space vector modulation (SVM) scheme is developed for the converter to control the input current and enable the soft-switching operation. In this paper, the topology derivation and circuit operational analysis for soft commutation are given. The proposed SVM scheme is introduced and a simulation is carried out to verify the circuit.