Interleaved zero‐voltage switching three‐level converter with less output inductor counts

Abstract

An interleaved three‐level converter with the new current doubler rectifier is proposed. The main advantages of the proposed converter are zero‐voltage switching (ZVS) turn‐on for all switches, low output ripple current and less voltage stress of the output diodes. Two three‐level converters connected in parallel are used to decrease the input current ripple, as well as to reduce the current rating of power switches. At the secondary side, two current doubler rectifiers sharing the same output filter inductors to reduce the output current ripple. Compared with the conventional centre‐tapped rectifier and current doubler rectifier, the adopted current doubler rectifier has less output current ripple. The output capacitance of the power switch and the leakage inductance (or external inductance) are resonant at the transition interval so that the power switches can be turned on under ZVS. The adopted converter can be employed in high voltage input and high current output applications. Experiments with a prototype with 750–800 V input and 48 V/30 A output are provided to verify the theory analysis.