A bidirectional isolated DC-DC converter

Aiming at the high switching voltage spikes and hard switching phenomena of traditional bidirectional isolated DC-DC converters, a bidirectional isolated DC-DC converter that can achieve zero voltage switching (ZVS) in the full power range is proposed. The two half bridges on the primary side of the converter are both Boost circuits, and the capacitor can clamp the voltage, which can increase the input voltage range and reduce the input current ripple. The secondary side is two active half-bridges connected in parallel, and the current of ZVS can be changed by adjusting the phase-shift angle of the secondary side. The converter adopts phase-shift + PWM control, which can make all the switching tubes realize ZVS in the full power range. First, introduce the working principle of the converter. Then, analyze the power transmission characteristics and soft switching characteristics of the converter. Finally, a simulation circuit is built to verify the advantages of the converter and its control strategy.