A novel zero-current-transition PWM DC-DC converter with coupled inductor

In this paper, a novel topology of a non-isolated buck converter with zero-current-transition (ZCT) capabilities is presented. In order to realize ZCT condition, the auxiliary circuit consists of a coupled inductor, a capacitor and an auxiliary switch, which also operates with a ZCT condition. It should be noted that the coupled inductor is comprised of three inductors on the same ferrite core which plays an important role in different branches. Moreover, the coupled inductor plays an effective role in achieving soft-switching condition. The detailed operating analysis of the proposed converter is presented. Finally, a 720 W prototype is built to verify the theoretical principles. The switching waveforms are also measured to validate the proposed topology.