Three-Port Bidirectional Series-Resonant Converter With First-Harmonic-Synchronized PWM

An isolated three-port bidirectional series-resonant converter with first-harmonic-synchronized pulsewidth modulation (FHS-PWM) is proposed for energy storage applications. With FHS-PWM control, the voltage conversion ratio is only determined by the effective duty cycle and has nothing to do with the amplitude and direction of the transferred power. The operating mode can be transited between the forward and backward modes automatically and smoothly. The voltage of the output and energy storage ports can also be regulated individually with decoupling control. Furthermore, with the help of auxiliary inductors, zero-voltage switching (ZVS) of all the switches can also be achieved within the entire operating range. The detailed operation principles, characteristics, design considerations, and control strategy of the proposed converter are analyzed. An experimental prototype is built and tested to verify the effectiveness and feasibility of the proposed solution.