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

This paper proposes a Zero-Voltage-Switching PWM, Hybrid Full-Bridge Three-Level Converter (ZVS 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 the half of the input voltage, and the switches can realize ZVS in a wide load range. The voltage stress of the switches of the two-level leg is the input voltage, and the switches can realize ZVS with the use of the leakage inductance of the transformer. 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 current of the converter has quite little ripple, so input filter can also be significantly reduced. The operation principle of the proposed converter is analyzed theoretically and verified by the experimental results.