Novel ZVS three-phase PFC converters and zero-voltage-switching space vector modulation

In three-phase PFC converter, there exist severe switch antiparallel diode reverse recovery problems. The effective measures of compound active-clamping and minimal voltage active-clamping techniques in single phase PFC are extended to three-phase PFC. A family of active-clamping ZVS soft switching PFC converter is derived. They can effectively suppress the diode reverse recovery and realize ZVS for all the switches. In order to reduce the number of switching for the auxiliary switch, A ZVS space vector modulation (ZVS-SVM) is proposed. The switching frequency of the main switch and the auxiliary switch is fixed. In the proposed circuit only one auxiliary switch is needed, which can realize ZVS for all the switches. At the same time the input current waveform is improved. One DSP controlled 4 kW ZVS compound active-clamping PFC converter prototype is implemented.