The Research On High-efficiency Bidirectional DC-DC Converter

The performance of the spacecraft power system is one of the important factors of the spacecraft mission. In the widely used solar arrays-battery power system, bi-directional DC-DC converters can effectively improve the power system power density by replacing the traditional independent battery charge and discharge modules. The project intends to design a bi-directional DC-DC converter to meet all the requirements in the actual application process.This paper has designed the hardware circuit of the bi-directional DC-DC converter. The inner current loop with outer loop voltage PWM conductance control are used to enhanced power levels and reduced the converter size, weight and cost under the premise ensuring low bus voltage ripple. After analyzing the working state of bi-directional Boost converter with coupled inductor, the parameter values of the main power topology were chosen. The design of feed forward triangular wave generator and the bidirectional current sensing circuit were built. The choices of the parameters for converter compensation network ensure that the converter possesses high stability and dynamic response under the bi-direction working. The simulation analysis has estimated the loss of the converter and verified the working status and parameter indicators of the converter with the selected parameters. Dynamic response and steady-state performance have been tested under the abrupt load on the bi-directional DC-DC converter working as the battery charge and discharge regulator respectively. Parallel experiments with different power levels for the converter have been designed to test the bus ripple.The simulations and experiments made in this article have verified the feasibility of bi-directional DC-DC converter in the solar arrays-battery power system. The entire power system is stable in different working status and has good performance under the energy bidirectional flow and abrupt load conditions.