开关磁阻电机系统可靠性研究

发布时间：2018-11-11 11:11

【摘要】：本文在分析总结电机系统可靠性研究现状的基础上，以开关磁阻电机系统为例给出了电机系统可靠性分析的方法。分析从系统级和器件级两方面进行。系统级分析以评价开关磁阻电机系统整体的可靠性水平为目标，综合考虑系统的拓扑结构、控制策略、元器件的各种故障模式及组合对开关磁阻电机系统可靠性的影响。在MATLAB软件平台上建立了开关磁阻电机功能故障仿真模型，分析了元器件各种故障模式及组合对开关磁阻电机系统性能的影响，并与实物系统运行结果进行了比较，验证了仿真模型的精确性。在此基础上结合故障仿真结果与Markov理论构建了开关磁阻电机系统的Markov可靠性模型，计算了开关磁阻电机系统的可靠性指标。器件级分析以功率MOSFET为主，，侧重分析了由功率MOSFET封装结构、封装材料与工作应力、环境应力相互作用而诱发的疲劳失效。首先，以有限元热仿真结果为基础，在MATLAB软件平台上创建了功率MOSFET的电-热耦合模型，对功率MOSFET内部封装各层的瞬时运行温度进行了估算；其次，结合雨流计数法、响应面设计法、热应力有限元仿真建立了功率MOSFET的热-机械耦合模型，给出了功率MOSFET累积塑性形变的计算方法；最后，以Miner线性累积理论为基础，结合功率MOSFET的电-热-机械耦合模型计算了器件的热疲劳寿命。在此基础上，总结并为后续系统改善设计及系统健康管理指明了方向。
[Abstract]:On the basis of analyzing and summarizing the present situation of the research on the reliability of the motor system, the method of reliability analysis of the motor system is given in this paper, taking the switched reluctance motor system as an example. The system level and device level are analyzed. The system level analysis is aimed at evaluating the reliability level of switched reluctance motor system. The system topology, control strategy, various fault modes of components and their combinations are considered comprehensively in order to evaluate the reliability of switched reluctance motor system. The functional fault simulation model of switched reluctance motor (SRM) is established on the platform of MATLAB software. The effects of various fault modes and combinations of components on the performance of SRM system are analyzed, and the results are compared with that of the real system. The accuracy of the simulation model is verified. Based on the fault simulation results and Markov theory, the Markov reliability model of switched reluctance motor system is constructed, and the reliability index of switched reluctance motor system is calculated. Power MOSFET is the main component level analysis. The fatigue failure induced by the interaction of power MOSFET packaging structure, encapsulation material and working stress and environmental stress is analyzed emphatically. Firstly, based on the results of finite element thermal simulation, the electric-thermal coupling model of power MOSFET is established on the MATLAB software platform, and the instantaneous operating temperature of each layer of power MOSFET is estimated. Secondly, combined with rain flow counting method, response surface design method and thermal stress finite element simulation, the thermal-mechanical coupling model of power MOSFET is established, and the calculation method of cumulative plastic deformation of power MOSFET is given. Finally, the thermal fatigue life of the device is calculated based on the Miner linear accumulation theory and the electric-thermal-mechanical coupling model of the power MOSFET. On this basis, the paper summarizes and points out the direction of system improvement design and system health management.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM352

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