ZERO-VOLTAGE AND ZERO-CURRENT-SWITCfflNG PWM HYBRID FULL-BRIDGE THREE-LEVEL CONVERTER

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 leg and a two-level leg. The voltage stress of the switches of the three-level leg is half of the input voltage, and the switches can realize ZVS in a wide load range, so 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 in a wide load range, so IGBT can be adopted. The secondary rectified voltage is a three-level waveform having lower high-frequency content compared with that of the traditional full-bridge converters, which can reduce the output filter, and as a result, the dynamic response of the converter is improved. The input filter can also be significantly reduced due to the little ripple of the input current. The operation principle of the proposed converter is analyzed and verified by the experimental results.