A novel zero voltage switched (ZVS) buck converter using coupled inductor

A novel zero-voltage switched (ZVS) buck converter using a coupled inductor is proposed in this paper. An additional winding is added on the same core of the output filter inductor for the purpose of commutation. The output inductor current is kept in continuous conduction mode (CCM) with small ripple. ZVS conditions for both switches are satisfied over wide load range. The converter can be operated at a fixed switching frequency. High switching frequency and high efficiency can be achieved due to soft switching. The proposed converter is analyzed in detail. Simulation is used to verify the analysis. The concept of ZVS using coupled inductor can also be applied to other PWM converters. ZVS-Boost and ZVS-Buck-Boost converters are derived based on the same concept.