一种简化混合双桥LLC谐振变换器以减少无源器件及损耗用于应急电源

The proportion of passive components loss in the total power loss of inductor–inductor–capacitor (LLC) resonant converters has reached a critical point. To address this issue, this article proposes a simplified hybrid dual-bridge LLC resonant converter to reduce passive component losses. It consists of a primary LLC resonant converter and an active clamp auxiliary bridge converter connected in parallel. The turn-off current of the LLC resonant converter over the entire range is greatly reduced by means of the clamping operation of the auxiliary converter. Compared with conventional dual-bridge LLC resonant converters, the proposed converter requires only one resonant tank, which can reduce the number of passive components; therefore, it can achieve a 26.5% resonance component cost reduction and a 13.8% total volume of inductor reduction. A 1.2-kW prototype of the hybrid dual full-bridge (FB) three-leg LLC resonant converters is built as a case study to validate the proposed approach. Compared to conventional dual FB three-leg LLC resonant converters, the proposed converter can achieve a 27% reduction in passive component losses without sacrificing soft switching performance.