考虑非预期电击穿的离子推力器可靠性分析

Reliability Analysis of Ion Thruster Considering Unexpected Electric Breakdown

针对离子推力器服役过程中的非预期电击穿对可靠性的影响问题,首先进行了非预期电击穿的失效影响及综合风险评估,然后结合非预期电击穿导致的突发失效特征建立了基于δ冲击模型的离子推力器可靠性评估模型,最后以20 cm Xe离子推力器为例,在收集地面试验历史数据的基础上计算了考虑非预期电击穿的离子推力器可靠度随服役时间的关系。另外,综合考虑了由于栅极系统性能退化导致的退化型失效和由于非预期电击穿导致的突发型失效共存的情形,对离子推力器的整机可靠性评估进行了分析讨论。

Aiming at the impact of unexpected electric breakdown on the reliability of ion thruster in service,firstly,the failure impact and comprehensive risk assessment of unexpected electric breakdown are carried out,and then combined with the sudden failure characteristics caused by unexpected electric breakdown,a reliability assessment model of ion thruster based on impact model is established.Finally,taking the 20 cm Xe ion thruster as an example,the relationship between the reliability of the ion thruster and the service time considering the unexpected electric breakdown is calculated on the basis of collecting the historical data of the ground test.In addition,the coexistence of degraded failure caused by grid system performance degradation and sudden failure caused by unexpected electric breakdown is comprehensively considered,and the overall reliability of ion thruster is analyzed and discussed.