Integrated magnetics scheme for ZVS hybrid converter with improved performance

This paper proposes a new integrated magnetics scheme for the ZVS hybrid DC-DC converter. The basic hybrid converter achieves significant reduction in filter requirement, while simultaneously achieving ZVS under all operating conditions. This paper attempts to remove one of the main drawbacks of the hybrid converter, namely the requirement of two power transformers, by combining them into a single magnetic structure with reduced volume. The proposed scheme also results in reduction of cores losses under a wide operating range. In addition, the integrated magnetics scheme improves the ZVS characteristics of the right-most leg switches at light loads, thus eliminating the extra LC circuit needed in the basic hybrid converter. The principle of operation of the proposed scheme is analyzed using the gyrator-capacitor model. Savings in core size and core losses compared to the basic hybrid converter are discussed. Experimental results from a 100 V/5 A proof-of-concept prototype validate the analysis, and demonstrate the advantages of the proposed scheme.