A family of novel zero-voltage switching three-phase PWM converters topology for distributed generation

Because of the need of energy saving and emission reduction, we see a quick increase of installed renewable energy distributed generation systems. Three phase PWM Grid-side converter is widely used for medium and large capacity distributed generation systems. Traditionally hard-switching three-phase PWM converters are used, which causes severe switching loss, high di/dt and EMI. In this paper, a family of novel zero voltage switching three-phase PWM converter topologies under two types of active clamping are proposed. Novel space vector modulation schemes for the three-phase PWM converter is proposed. With the proposed space vector modulation scheme, the converters can realize zero voltage switching (ZVS) operation for all switching devices while the anti-parallel diode reverse recovery of all switch devices is suppressed. It has features fixed switching frequency, and lower voltage stress of the power switch devices. The different converters in the family are compared with respect to soft switching conditions, stress, adaptability to DC side voltage variation. Prototypes are built to verify the theory.