Abstract: The application of electric propulsion system in China’s geostationary satellite in the future is a necessary trend．For the application of the electric propulsion system，a lot of problems have to be solved for both thruster itself and the system application．Based on the analysis of satellite requirements，this paper summarizes the key techniques for the electric propulsion system application on the geostationary satellite．These problems can bese parated into three aspects：the first is the internal interface of the electric propulsion system，including the interface between thruster and propellant storage and supply subsystem，power subsystem，control subsystem etc．The second is the coordinate operation of electric propulsion system and chemical propulsion system，including the separate operation and interaction．The last one is impact of the electrical propulsion system on the whole satellite，including plume，electromagnetic compatibility(EMC)，telemetry，tracking and control(TT&C)and power etc．This paper classifies and integrates the key techniques and defines the problems to be solved for the application of electric propulsion system in China 7Sgeostationarysatellite．

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