ZVS combined three-level converter - A topology suitable for high input voltage with wide range applications

A novel zero-voltage-switching (ZVS) combined three-level (TL) converter is proposed in this paper. It is essentially a hybrid combination of a half-bridge TL section and a full-bridge section. The main advantages of the proposed converter are given as follows: the voltage stress of all the switches is ensured to be only half of the input voltage; the secondary rectified voltage is very close to the output voltage, so the high-frequency content is very low, leading to a reduced output filter requirement; the voltage stress of the rectifier diodes is also reduced; and the switches can achieve ZVS with the use of the leakage inductances of the transformers and the intrinsic capacitors of the switches. This paper describes the operating principles and design procedures for the proposed converter. Experimental results from a 1080 W prototype converter operating at 100 kHz are presented to validate the theoretical analysis and demonstrate the performance of the proposed converter.