Zero-voltage and zero-current-switching PWM hybrid full-bridge three-level converter

Abstract

This paper proposes a zero-voltage and zero-current-switching PWM hybrid full-bridge three-level converter (ZVZCS PWM H-FB TL converter), which has a three level (TL) leg and a two-level leg. The voltage stress of the switches of the TL leg is half of the input voltage, and the switches can realize ZVS, so the MOSFET can be adopted. The voltage stress of the switches of the two-level leg is the input voltage, and the switches can realize ZCS, so IGBT can be adopted. The secondary rectified voltage is a TL waveform having lower high-frequency content compared with that of the traditional FB converters, which leads to the reduction of the output filter inductance. The input current of the converter has quite low ripple, the input filter can also be significantly reduced. The operation principle of the proposed converter is analyzed and verified by the experimental results. Several ZVZCS PWM H-FB TL converters are also proposed in this paper.