Research on a High Voltage Isolated Resonant DC/DC Circuit

The input is alternating current (AC) and the output is direct current (DC) with adjustable positive and negative in the field of energy storage, vehicle charging, programmable power supply and other fields. AC input and DC output are generally isolated for security reasons. This paper adopts a three-stage topology to achieve this function, the front stage is a PWM rectifier circuit to achieve AC to DC conversion, the intermediate stage is an isolated Step-down circuit to achieve isolation, and the back stage is an H-bridge inverter circuit to achieve positive and negative bi-directional output. The topology of intermediate high voltage isolated resonant DC/DC circuit is introduced. The working mechanism and main parameter selection design of the soft switch are analyzed and calculated in detail. A 200W experimental prototype is developed and the correctness of the circuit design is verified by the experimental results.