Application of Step-Down Controllable Rectifier Circuit in Spacecraft Radio Power Transmission System

In response to the high requirements for miniaturization and low voltage high current systems in aerospace satellites, a single-stage solution of a receiving end step-down controllable rectifier was designed to be used in conjunction with SS compensation topology, replacing the traditional two-stage solution of uncontrolled rectification and buck circuit. The step-down controllable rectifier integrates a diode rectifier circuit into a two-phase interleaved parallel step-down circuit to achieve bridge arm reuse, reduce system volume, and improve system power density. On the premise of SS compensation topology, this article analyzes the different modal changes of the step-down controllable rectifier under the working conditions of duty cycle 0 to 0.5 and 0.5 to 1, and derives the expressions of the converter in steady state and transient state, guiding the sampling and control methods. Furthermore, the hardware and software implementation of the step-down controllable rectifier are designed. Finally, an experimental platform with an output power of 600 W and an output voltage of 31 V is built for testing. The efficiency of the receiving end converter reaches 95.3%, and the power board after thermal balance is 67 ℃, which meets the design requirements and can be widely used in the development of low-voltage high current wireless charging systems.