Isolated DC to three-phase AC converter using indirect matrix converter with ZVS applied to all switches

This paper proposes a Zero Voltage Switching (ZVS) method for an isolated DC to three-phase AC converter using an indirect matrix converter at the secondary side of the transformer. Phase-shift control is applied to the inverter at the primary side of the transformer, while Pulse Density Modulation (PDM) is employed to the indirect matrix converter at the secondary side. The inverter at the secondary side achieves ZVS by synchronizing the gate pulses with the zero voltage period of the input voltage. As a result, the proposed method reduces switching losses of both two converters. The validity of the proposed method is confirmed by experiment with a 3-kW prototype. From the experimental results, the snubber loss generated by the leakage inductance which satisfies the conditions for ZVS is small and almost constant against the output power. It is concluded that the efficiency of the entire range of load with proposed control is improved by 2% in comparison to the isolated DC-AC converter using matrix converter. In addition, the loss of the inverter at primary side is reduced by 64.5% at rated output.