An Optimized Zero-Voltage Zero-Current Transition Boost Converter Realized by Coupled Inductor

In this paper, a new zero-voltage zero-current transition (ZVZCT) boost converter using coupled inductors is proposed. The feature of this topology is: the main switch can be switched ON with ZVZCT, and OFF with zero-voltage switching, without any voltage and current stress. The auxiliary switch is turned ON with zero-current switching. Other semiconductor devices can also achieve soft switching (SS). Due to the existence of the coupling effect, the current impact of the auxiliary switch is completely suppressed when it is turned OFF. Lower input current and output voltage in the interval of the switch-OFF for the auxiliary switch are just equivalent to running at a low power level, which is an additional advantage of the coupled inductor ZVZCT solution. Another advantage of the topology is that the SS condition of the main switch for each specific load can be effectively optimized just by setting the ratio of coupling inductance corresponding to the circuit design and application load. Thus, the topology design can be improved to adapt to different load types. A 100 kHz experimental prototype has been verified, different load for 1 and 0.4 kW optimization comparison has been presented, and the case without optimization is also observed.