Development Of 3kW New Power Conditioning Unit For Satellite

The Power Conditioning Unit(PCU)is the center ofthe satellite energy regulation.The Power Conditioning Unit keeps the stability of the satellite bus at all stages of the satellite in orbit,such as sun,eclipse,and so on.It determines the success or failure of the satellite mission whether the Power Conditioning Unit is stable or not.With the vigorous development of China's space industry,the satellite has put forward higher and higher requirements for the conversion efficiency,bus stability,reliability and life span of the Power Conditioning Unit.Past products have been unable to meet the new mission requirements of satellites.This thesis develops a new-type 3kW Power Conditioning Unit to meet the application requirements of the medium Earth orbit satellites.This thesis analyzes the actual interface requirements and power demands of the satellite on orbit,and determines the system adjustment framework based on the Sequential Switching Shunt Regulator mode through the research of the Power Conditioning Unit scheme.Using the Main Error Amplifier as the main control signal,the PCU is divided into three main power circuits which include the Battery Charging Regulator,the Battery Discharging Regulator and the Sequential Switching Shunt Regulator.The key circuit is analyzed and simulated in detail.In order to reduce the volume and weight of the product,the Battery Charging Regulator and the Battery Discharging Regulator are integrated into the charge and discharge regulation module.The main power circuits and control circuits in the product have been designed with redundancy to improve the reliability of the product.Many advanced technologies,such as over current protection,current limiting protection and battery overcharge protection,are also adopted to improve product safety.In order to simulate all kinds of working conditions of the PCU on orbit,a test system is built with battery simulator and solar simulator.The key circuit characteristics of the PCU,such as bus margin and output impedance,are tested comprehensively.The evaluation results in terms of performance and reliability test show that the specifications of the new-type PCU meet the requirements.The reliability and lifetime of the Power Conditioning Unit are also verified.The research results can be applied to all orbit satellites whose platform power demand does not exceed 3kW in China.