High Reliability Electronic Reconnaissance Satellites Secondary Power Supply

The power of satellites spacecrafts are generally provided by chemical cell or solar power batteries with a single voltage grade. Whereas, for various equipments fitted on satellites, the voltage grade, precision and energized style generally show significant distinctions, so the secondary power supply with an excellent performances must be designed to meet the requirements above.With the rapid development in the field of space technique, as a new kind of space electronic war, much research on Electronic reconnaissance satellite has been carried out.As the main load of electronic reconnaissance satellite, the electronic reconnaissance sub-system is more complicated, and which is constructed by various single machines. So, the secondary power supply needs to be designed to meet the requirements in varsity, power grade, reliability, etc.The paper introduced the development of secondary power supply, as well as the background and value for application, then, described the key procedure and methods for designing the high reliable electronic reconnaissance satellite, and adopts the PWM switch technique in its realization.The main circuit adopted the push-pull type by comparing several typical topologies, and realized the auxiliary power supply isolation, voltage feedback, as well as the transformer isolation drive during the whole solution. To meet the requirement of high performance, used the astatic regulator control technique and the PWM integrated circuit SG1525A produced by SG company, and its construction and peripheral circuit was described. Furthermore, the aftercooling and auxiliary power supply thermal redundancy technique were used to enhance its reliability for output channels.Adopts the two grated filter to degrade the voltage ripple, and use thermal resistance calculation and verification experiment to check the result of thermal design schedule, with the consideration of high power, EMC capability and high frequent operation. So, the temperature of electrical element can be controlled in the expected range. Moreover, various protection circuits are designed, such as over-current protection, over-voltage protection, bus protection, RC absorber circuit and EMI filter. So, this power supply exhibits many merits: high reliability, precision and efficiency, low ripple, perfect protection and good EMC performance.The system has been tested performance and validated experiment, and worked for three years, showed good performance. The whole project meets the expired requirement and results, also provides affluent experience and good foundation for the design of auxiliary power supply.