A Four-Port Resonant DC/DC Converter Topology and its Soft-Switching Optimization Design Method

Aiming at the multienergy integration application, a four-port resonant dc–dc converter based on the multiwinding transformer is proposed. To solve the power decoupling problems of the dc–dc converter based on the multiwinding transformer, the passive network of the transformer utilizes symmetric LC resonant branches to eliminate power coupling between multiple ports and eliminate gain deviations due to transformer leakage inductance's impact at the hardware level, which avoids complex decoupling control and controller's burden. Besides, to optimize the zero-voltage switching (ZVS) performance of the four ports, an auxiliary inductance is introduced into a single port to optimize the ZVS of two-sided ports. Meanwhile, time-domain analysis is adopted to accurately analyze the operational principle and solve the numerical results to lay the foundation for analyzing the impact factor of ZVS. On this basis, an optimized parameter design method is proposed, which mainly refers to the parameter of the resonant impedance and auxiliary inductance adhering to the objective of achieving ZVS for each port. Then, with the help of auxiliary inductance and parameter design, the ZVS of all switches can be achieved. Furthermore, a 42 kW experimental prototype is constructed to validate the effectiveness of the proposed power decoupling and parameter design method.