A ZVS PWM three-phase inverter with active clamping technique using only a single auxiliary switch

This paper presents the analysis of a ZVS PWM three-phase inverter with active voltage clamping technique using the reverse recovery energy of the diodes to improve the converter efficiency. The structure is particularly simple and robust. It is very attractive for three phase high power applications. Conduction and commutation losses are reduced due to implementation of a simple active snubber circuit that provides ZVS conditions for all switches, including the auxiliary one. Its main features are: simple control strategy, robustness, lower weight and volume, lower harmonic distortion of the output current, and high efficiency. The operation principle for steady-state conditions, mathematical analysis and experimental results from a laboratory prototype are presented.