Power Loss Analysis And Improvement Of High Voltage Hall Thruster

With the development of power technology and the proposal of all electric propulsion satellite platform,the demand for high power and high specific impulse engines is increasing at this stage.The most effective way to improve the specific impulse of Hall thruster is to improve the discharge voltage.However,the performance of the traditional Hall thruster is greatly reduced at high voltage,and the design of the thruster has to weigh high specific impulse and high efficiency.Therefore,the main reason for the decline of the Hall thruster efficiency at high voltage is of great significance to the design of high voltage Hall thruster.The main work of this article is as follows:First,the experimental study of the wall thermal deposition in the discharge channel is carried out.The analysis of heat flux in the heat balance stage is used to diagnose the wall heat flow through the measurement of wall temperature.The difference of wall heat flux with discharge voltage under high voltage and low voltage is contrasted,and the reason is explained.Meanwhile,the wall heat flux is significantly reduced by magnetic field extrapolation,which lays the foundation for the optimization of high voltage thruster.In addition,a new idea for electronic probe diagnosis of heat flux to distinguish electron heat flow and ion heat flow is proposed,and verified the feasibility of theory by using thermal simulation.Secondly,the experimental study of anode thermal deposition is carried out.Using the thermal dynamic characteristics of anode shutdown and based on instantaneous lumped parameter method assume,measuring the rate of the decline of anode temperature to calculate anode heat flow.The influence of discharge voltage,magnetic field intensity and discharge current on the anode heat flux are discussed,and analysis its mechanism briefly,explore the optimal method of reducing anode heat flux,and provide the basis for the high voltage Hall thruster anode thermal process optimization.Thirdly,establishing a reasonable system of energy loss by analysis Hall thruster energy transformation process and the ultimate role of the energy as the classification criteria,and gives experimental evaluation methods of main loss.The main energy loss characteristics and the change rule of discharge voltage are studied by means of experiment,and the dominant energy loss mechanism is found out.Finally found differences in energy loss characteristics under low voltage and high voltage,found the main energy that restrict high voltage Hall thruster efficiency,direct a right way for the next step optimization of the high voltage Hall thruster design.Finally,HEP-100 HV Hall thruster was optimized,including the discharge channel morphology optimization and optimization of magnetic field magnetic field extrapolation,and verified in the variable cross-section channel and with the performance and discharge characteristics of the structure under the magnetic field extrapolation.The stable working interval of the thruster is widened,and the long time stability under the 900 V voltage is realized,and there is no overheating.At the same time,the plume boundary is clearer,and more close to the magnetic focusing mode,the anode specific impulse reaches 3467 s,the anode efficiency is 64.8%,and the efficiency is higher than the international typical high discharge Hall thruster.