Interleaved zero current transition three-level buck converter

This paper introduces a four-switch interleaved zero current transition three-level (ZCT TL) buck converter with two sets of switches which operate out of phase and share the load power equally. The addition of four small auxiliary inductors allows turn-on transitions at zero current and a significant reduction of the losses associated with diode reverse recovery. This circuit is intended for high-voltage high-power applications. The paper describes an experimental 25 kW constant power source having an input voltage of 1,400 Vdc. Full output power can be obtained over an output voltage range from 300 Vdc to 1300 Vdc. Losses and efficiency of the experimental prototype compare favorably against the hard-switched case, and previously proposed ZCT schemes.