Design And Start-up Characteristics Of Electric Propulsion Hollow Cathode Power Supply Circuit

As the heart of the space thruster,the hollow cathode has great influence on the performance of the thruster and spacecraft.The traditional hollow cathode ignition usually requires more power sources to supply power separately,which makes the power supply complex and huge.The problem of the ignition voltage and current oscillation of the hollow cathode during start-up also needs to be solved.In addition to the optimization of the cathode structure,it can also be discussed from the external power supply module and power supply strategy.Therefore,in view of the above problems,this paper conducts the following researches:By studying the thermally start ignition characteristics of hollow cathode,compared the cathode power supply power supply and the difference between the external power module directly,summarizes the thermally start hollow cathode demand of power supply and power supply device.Through the thermally start of hollow cathode,the ignition circuit selection,push-pull circuit is chosen as the cathode of the ignition module,ignition module are behind in the topology as the foundation,finally put forward a kind of thermally start power supply circuit design method of the hollow cathode,for subsequent chapters power system integration design laid a foundation.In this paper,the starting circuit design of the heaterless hollow cathode was carried out,the design methods of the external ignition module and the contact module were proposed,the influence of the starting circuit on the cathode starting was studied,and the influence of inductance and capacitor on the starting characteristics of the external starting cold cathode was compared.The differences between the external power supply module and the traditional multi-power supply are compared,such as the starting time,the oscillating amplitude of voltage and current,and the spike pulse at the starting moment.Start discharge was optimized from the angle of plasma discharge circuit,this paper proposes a optimized emitter structure,with a high speed camera records the cathode the boot process,compared with two kinds of emitter cathode structure difference of ignition,found the throttle type emitter cathode has higher heat flux at the emitter,and straight tube type emitter of central heat deposition on tantalum tube.The structure of emitter has great influence on the cathode start-up process.By adopting throttling emitter structure,the cathode heating efficiency can be effectively improved and the cathode start-up time can be reduced.Based on the integrated design of electric propulsion hollow cathode discharge module,the integrated method of power supply system is proposed,two power supply strategies are proposed,and the 2 ignition strategies are compared.The influence of different ignition input current,heating time and capacitor inductance on the power supply characteristics is verified.Finally,the tank discharge verification of the cathode power supply is carried out to verify the feasibility of the integrated design of the electropropulsion cathode power supply system.