Research on the Isolated Three-Port DC-DC Converter with Resonant Parameter Compensation Capability and Its Performance Optimization

In order to eliminate the adverse effects caused by power coupling of the isolated three-port converter (ITPC), this paper proposes a three-port resonant converter that uses a switch-controlled-capacitor (SCC) and an auxiliary inductor, which has resonant parameter compensation capability (RPC-ITPC). The topology and operational principle of RPC-ITPC are discussed in detail. To achieve resonant-type power decoupling, it is usually necessary to ensure that the resonant frequency of the decoupling port resonant tank is consistent with the switching frequency, which puts high demands on the accuracy of the resonant components. To address the sensitivity of resonant-type power decoupling to the parameters of resonant components, an SCC was adopted to solve the problem. The use of SCC enables the RPC-ITPC to have resonant parameter compensation capability. In order to further optimize the performance of the RPC-ITPC, a triple-phase-shift (TPS) modulation strategy is proposed to achieve the minimum RMS value of resonant current (MRMS-TPSMS). Under the MRMS-TPSMS, the switching devices of the power decoupling port have difficulty achieving ZVS turn-on. To circumvent this problem, we realize ZVS of the decoupling port switching devices via auxiliary inductor current injection. Finally, a 1 kW experimental prototype was constructed to validate the theoretical propositions presented in this study.