Research on Power Decoupling and Parameter Mismatch of Three-Port Isolated Resonant DC–DC Converter Applied Switch-Controlled Capacitor

In order to realize the controllable power decoupling and eliminate the influence of the parameter error of the resonant elements, a three-port dc–dc converter applied switch-controlled capacitor (SCC) is proposed. The operating principle and transmission power expression of the proposed three-port converter under triple-phase-shift control are analyzed. By adjusting the phase-shift angle of the SCC to adjust the resonant frequency of the resonant tanks, the topology-level power decoupling of the circuit at a constant frequency can be achieved. The addition of switch-controlled capacitors provides more freedom for power regulation between ports. Besides, according to the proposed converter, a design method for the parameters of the resonant tank is proposed to eliminate the adverse effects caused by the parameter error of the resonant elements. Then, an optimized triple-phase-shift modulation strategy is adopted to achieve the minimum rms value of the resonant converter. An experimental prototype was designed to verify the correctness of the proposed converter and modulation strategy.