A control method for a single-to-three-phase power converter with an active buffer and a charge circuit

This paper proposes a new circuit configuration and a control method for a single-phase to three-phase power converter with power decoupling function. The proposed converter does not require a large reactor and large smoothing capacitors in the DC link part. Large smoothing capacitors are conventionally required in such converters to absorb the power ripple with a frequency that is twice of the power supply. The proposed topology is constructed based on an indirect matrix converter with an active buffer to decouple the power ripple. The buffering energy is kept by the voltage variation of the capacitor instead of its capacitance. In addition, the transfer ratio between the input and output voltage is obtained to 0.707 due to the connected charge circuit. In this paper, the fundamental operations of the proposed converter are confirmed by simulation and experiment results. As the experimental results, the input current THD and the output current THD are 3.17% and 3.64 %, respectively. The input power factor (P.F.) of over 99 % is obtained. In addition, the maximum efficiency of over 90.2% (input voltage = 100V) or 94.6 % (input voltage = 200V) is obtained by prototype.