Development Of Power Conditioning And Distribution Unit For Small Satellite

The power system is a pivotal subsystem of satellite,it is used to supply power for other subsystem and payload.Therfore,it's performance,lifetime,weight and price has significant influence on satellite overall design.In order to improve power system performance and price indexes,the satellite power supply and distribution function are integrated into the small satellite power system,which is based on the design idea of standardization,modularization and extensibility.So it is extremely necessary with a single device to complete satellite power control,busbar distribution,the initiation sensitivity and heater control and so on.For this reason,it is a great practical significance to develop Power Conditioning and Distribution Unit.The PCDU function,technical index and design scheme are proposed in this thesis through studying the research situation of PCDU both in China and abroad.The whole device and each function module are designed with standardization,modularization and scalability.This paper analyzes the demand of PCDU in orbit,the PCDU is divided into four modules,including Power Conditioning Unit,busbar distribution,electro explosive lines and TMTC.The PCU uses the shunt unregulated bus topology with sun sequential shunt switch to achieve the solar array of power supply and shunt control,implement constant current and voltage charging and discharging of the battery,form the busbar of satellite;The busbar distribution module take charge of the load control with latching current limiter to achieve protect of over current and fault isolation quickly;electro explosive lines mod ule accomplish Pyrotechnics control functions with relay and MOSFET control;As the brain of PCDU,TMTC accomplish the function of telemeasure and telecommand with main and prepare that only one work to increase the reliability.After practical application and test of the PCDU,it is proved that each module of the equipment achieves the design requirements and also satisfies the overall technical requirements.