基于故障树-蒙特卡罗模拟的电动飞机推进系统可靠性分析

Reliability Analysis of Electric Aircraft Propulsion System Based on Fault Tree-Monte Carlo Simulation

随着新能源电动飞机的不断发展,电动飞机适航性与可靠性的研究是未来电动飞机发展的重要方向。本文首先分析国内外电动飞机推进系统在适航审定以及安全性分析方面的现状,明确目前适航审定以及可靠性分析中的难点;然后利用某仿真软件对国内某典型电动飞机的推进系统进行建模仿真,参考国内外适航标准以及美国国家航空航天局(NASA)数据库确定故障模式并建立推进系统系统故障树,得到推进系统故障树的最小割集以及其符合的分布函数作为蒙特卡罗仿真的输入值;最后利用某仿真软件对推进系统进行蒙特卡罗仿真,结合底事件可靠性函数对顶事件可靠性进行估计,并与实际运行数据进行对比来验证仿真正确性。结果表明,冷却损失、热失控、外部短路/开路、电池管理系统故障是推进系统的薄弱环节,推进系统平均故障间隔时间(MTBF)为6956.7h,为未来电动飞机适航取证及可行性验证提供参考。

With the continuous development of new energy electric aircraft,the research on airworthiness and reliability of electric aircraft is an important topic for the development of electric aircraft in the future.Firstly,the current situation of airworthiness certification and safety analysis of electric aircraft propulsion system at home and abroad is analyzed,and the difficulties in airworthiness certification and reliability analysis are clarified.Then,Simulation Software is used to model and simulate the propulsion system of a typical electric aircraft in China,and the fault mode is determined by referring to the airworthiness standards at home and abroad and the database of the NASA,and the fault tree of the propulsion system is established.The minimum cut set of the fault tree of the propulsion system and the distribution function it conforms to are used as the input values of Monte Carlo simulation.Finally,the Monte Carlo simulation is carried out by using Simulation Software,and the reliability of the top event is estimated by combining the reliability function of the bottom event,and the correctness of the simulation is verified by comparing with the actual operation data.The results show that cooling loss,thermal runaway,external short circuit/open circuit,and battery management system failure are the weak links of the propulsion system.The MTBF of the propulsion system is 6956.7h,which provides a reference for future airworthiness certification and feasibility verification of electric aircraft.