脉冲等离子体推力器等效电路模型分析

Analysis of equivalent circuit model for pulsed plasma thruster

脉冲等离子体推力器(PPT)的放电电流与推力器性能有密切关系。为了分析影响脉冲等离子体推力器放电电流的因素,建立了推力器放电过程中的等效电路模型,分析了等效电路中电感及电阻的分量,并对简化的等效电路模型进行解耦,得到了放电电流的3种状态。通过实验以及方程解耦,得到了实际电路中的等效电感及等效电阻值,研究了等效电感及电阻中影响推力器性能的因素。结果表明,推力器的间距和放电能量改变了等离子体的电感及电阻值,从而改变了放电电流曲线,影响了推力器的电磁加速性能。设计PPT时,应尽量减小电极的寄生电感和电阻,采用内感和内阻较小的放电电容,获得较高的PPT效率。

The discharging current of pulsed plasma thruster （PPT） has close relation with thruster property. In order to analyze some factors affecting discharging current of pulsed plasma thruster （PPT） , equivalent circuit model during discharge process was derived. Inductance and resistance component in equivalent circuit were analyzed. By solving the equation of simplified equivalent circuit model, three kinds of discharging current states were obtained. Through the test and solution of equation, the actual inductance and the resistance were obtained. The factors affecting the thruster property were investigated. The results show that electrode gap and discharge energy can change inductance and the resistance of plasma so as to affect discharging current curve and electromagnetic acceleration performance. During PPT design process, the parasitic inductance and resistance of the electrode should be minimized to obtain high efficiency.