基于谐振电容部分能量调节的多相交错LLC变换器新型均流方案

In this article, a novel current sharing scheme for multiphase interleaved LLC converter by regulating part of the energy stored in the resonant capacitor is proposed. The energy regulation of the resonant capacitor is realized with the energy shift cell (ESC). Two different ESC structures named phase-to-phase ESC (PESC) and individual ESC (IESC), respectively, have been proposed. By combining with the phase shift control, excellent output current balance and reduced current ripple can be achieved simultaneously. Owing to the merits of partial energy regulation and zero voltage switching (ZVS) for the switches in ESC, the increased losses brought by ESC are small. Detailed analysis of the operation principle and design considerations have been presented. Finally, two 12 V/40 A two-phase interleaved LLC laboratory prototypes adopting PESC and IESC, respectively, have been built up and compared to verify the feasibility of the proposed scheme.