离子推力器多模式化研究

为了实现离子推力器多模式化,分析了离子推力器功率宽范围调节限制因素,提出了两种宽范围调节策略;针对我国小行星探测任务,完成了30cm多模式离子推力器研制、功率宽范围调节限制条件确定、以及两种调节策略下多模式工作点设计及对比研究。结果显示,通过降低放电室磁场强度可延伸离子推力器最小稳定工作功率,提高束流均匀性,实现离子推力器更宽功率范围多工作点设计;功率宽范围调节主要是屏栅电压和束电流的宽范围调节,二者通过栅极导流系数限制和交叉限制而约束;推力随功率增加呈线性增加关系,比冲随功率的增加总体上呈先快速增加后趋于稳定的趋势;30cm多模式离子推力器在0.25kW～5kW内稳定工作,推力10mN～186mN,比冲1522s～3586s。

Research on Multi-Mode Realization of Ion Thruster

Multimode work has gradually become an essential characteristic of ion thruster. How to design multimode ion thruster and how to determine the multimode operation parameters are the key technologies to realize multimode operation of ion thruster. The limiting factors of deep power throttling of ion thruster are analyzed and two throttling strategies are put forward. To meet the application requirement of Chinese asteroid exploration, the 30cm multimode ion thruster has been developing and its power throttling limiting conditions are also determined. While operation points under two throttling strategies are designed and compared. The stable operation of the 30cm ion thrust is realized at 41 working points over an input power range from 0.25kW to 5kW. The results show that by reducing the magnetic field intensity of the discharge chamber, the minimum stable working power of the ion thruster can be extended and the uniformity of the beam current density can be improved to achieve a wide power range and multi working points of the ion thruster. Multimode operations over a wide range of power is realized by adjusting beam current and screen grid voltage,while they are constrained by grid system crossover limit and perveance limit. The double-grid system has a wider power range than three-grid system. The thrust increases linearly with the increase of power and the specific impulse increases rapidly first and then tends to be stable.