A Self-Driven Current-Doubler-Rectifier Three-Level Converter With Integrated Magnetics

In this paper, a self-driven current-doubler-rectifier (CDR) three-level (TL) converter with integrated magnetics is proposed. The TL half-bridge (HB) structure without clamped diodes and flying capacitor is used as the primary-side structure, the current ripple of output inductors is reduced secondly, the main transformer is split into two transformers and their magnetizing inductors are employed as output inductors, and finally, these two transformers are integrated into one core. Compared to traditional zero-voltage-switching (ZVS) CDR TL-HB converter, the proposed converter have several advantages, the current ripple of output inductors is smaller, the number of magnetic component is only one by using the integrated magnetic method, the windings of main transformer can be directly used to drive synchronous rectifiers to realize self-driven, and the problem of poor clamped diode reliability in traditional ZVS CDR TL converter is eliminated. A 28 V/100 A prototype is built in lab to verify the theoretical analysis. Experimental results show that it can achieve 97.1% efficiency at full load.