Efficiency optimization design of modular hybrid wide voltage regulating DC transformer

Modular input series output parallel DC transformer has a wide application prospect in medium and low voltage DC distribution network. In order to solve the problem of low efficiency of DC transformer in wide voltage regulation range, the efficiency optimization design of hybrid wide voltage regulation DC transformer is proposed. Firstly, the efficiency characteristics and voltage regulation ability of dual ative bridge (DAB) module and CLLLC module are compared in detail. The analysis conclusion shows that CLLLC module has high efficiency under heavy load, but the voltage regulation ability is limited. The DAB module has wide voltage regulation ability, so the hybrid DC transformer can realize the complementary advantages of the two, making the DC transformer more flexible and efficient. Then, the soft switch optimization design of DAB module and CLLLC module is analyzed in depth, and the optimization design process of module ratio is proposed in combination with the voltage regulation range and efficiency. Then, the detailed design description is carried out in combination with the specific experimental scene. An experimental prototype with input 500 V, output 100 V and 2.5 kW power is built to verify the effectiveness of the theoretical analysis and design method.