Voltage Clamping Scheme for Zero-Voltage-Switching PWM Combined Three-level Converter

Zero-voltage-switching (ZVS) PWM combined three-level (TL) converter realizes ZVS for the switches with the use of the leakage inductances or resonant inductance and the output capacitors of the switches, however the rectifier diodes still suffer the voltage oscillation resulted by the reverse recovery. In order to solve this problem, this paper introduces two basic clamping tanks to ZVS PWM combined TL converter and proposes a family of voltage clamping schemes. Two feasible schemes are adopted which can not only eliminate the voltage oscillation and spike both in 3L and 2L mode, but keep all the advantages of the original converter. A prototype converter has been tested for the verification of the principles and advantages