Research on Efficiency Optimization Technology of CLLLC Resonant Bidirectional DC / DC Converter

The research on CLLLC resonant converters usually improves transmission efficiency by optimizing the parameter design, but the converter efficiency is low at light load. In this paper, this paper uses the optimal asymmetric voltage offset (OAVC) control to realize the active bridge converter's wide range of soft switching operations. The optimal equivalent resistance is obtained by the fundamental wave equivalent of the circuit, and the transmission efficiency is optimized under the adaptive load. The constant voltage output is realized by adjusting the inverter side switch tube, and the optimal equivalent resistance is obtained by changing the rectifier side switch tube. Finally, through multiple sets of simulation tests, it is verified that the efficiency of the proposed method is maintained above 90% under different load conditions. Under the light load condition with an output power of 100 W, the efficiency of the proposed method is improved by 30% compared with the traditional method, achieving high-efficiency transmission.