摘 要

Abstract II

1 绪论 1

1.1 研究的目的及意义 1

1.2国内外故障树研究的发展及现状 2

1.3 本文的研究内容 2

2 故障树理论的基本内容 3

2.1 故障树的基本概念 3

2.2 故障树分析法常用逻辑符号 3

2.2 故障树分析的顺序及特点 3

2.4 故障树的建造过程 4

2.5 本章小结 5

3 故障树算法 5

3.1 故障树与结构函数 7

3.2 布尔代数规则 8

3.3 相干性与相干结构函数 8

3.4 故障树定性分析 9

3.5 最小割集算法 10

3.5.1 故障树最小割集的三种算法 10

3.5.2 算法应用举例 10

3.6 由最小割集表示的结构函数 11

3.7 故障树的定性分析 12

3.7.1 有n个独立事件的定量分析 13

3.7.2 有n个相斥事件的定量分析 13

3.7.3 有n个相容事件的定量分析 14

3.8 最小割集表示的结构函数顶事件发生概率 14

3.9 不交和展开法求顶事件发生概率的精确解 14

3.10 求顶事件发生概率的近似解 15

3.11 事件重要度计算 16

3.11.1 有n个独立事件的定量分析 16

3.11.2 有n个独立事件的定量分析 16

3.11.3 有n个独立事件的定量分析 16

3.12 本章小结 16

4 异步电动机故障诊断 17

4.1 异步电动机故障树构建 17

4.2 定性和定量分析 18

4.3 本章小结 19

5 电动机故障树的MATLAB仿真 19

5.1 故障树仿真 19

5.2 仿真原理 20

5.3 本章小结 20

结束语 22

参考文献 23

附 录 25

附录1 程序源代码 25

致 谢 30

摘 要

电动机的稳定运行对于自动化流水线企业的正常生产工作而言非常重要，这一点与企业生产效率息息相关。在生产过程中，电动机难免会发生故障，而对故障进行维修时的关键在于能否准确诊断出故障出处。通过准确判定故障出处及时对电动机进行检修，并减少维修所需人力物力成本。

故障树分析(Fault Tree Analysis，简称FTA)又称事故树分析，是安全系统工程中最重要的分析方法。事故树分析从一个可能的事故开始，自上而下、一层层的寻找顶事件的直接原因和间接原因事件，直到基本原因事件，并用逻辑图把这些事件之间的逻辑关系表达出来。

本文对电动机故障树进行了初步研究和探索，提出了构建电动机故障树实现方法。详细说明了故障树分析法中常用的结构函数等数学工具，列举了上行法，下行法，布尔割集法三种主流用于分析最小割集的算法，并举例对三种算法进行说明。

文中首先分析了国内外研究现状及研究的意义，之后给出了构建异步电动机故障树方案，并且具体分析了异步电动机可能出现的各类故障，列举出了其最小割集。另外，通过matlab对异步电动机故障树的仿真，更加直观地反映电动机可能的故障原因，论证了结果的正确性，验证了故障树分析法的应用价值。最后对本次毕业设计进行总结，同时提出不足和展望。

关键词：异步电动机故障；故障树分析；故障树matlab仿真；

Abstract

The stable operation of the motor is very important for the normal production work of the automated assembly line enterprise. In the production process, the motor will inevitably fail, and the key to the maintenance of the fault lies in the accurate diagnosis of the fault. Through the accurate determination of the failure to timely repair the motor, and reduce the manpower and material costs required for maintenance.

Fault tree analysis (FTA), also known as accident tree analysis, is the most important analysis method in safety system engineering. Accident tree analysis begins with a possible accident, the top-down, layer-by-layer search for direct causes and incidents of indirect causes until the cause of the basic cause, and uses a logic diagram to express the logical relationship between these events.

In this paper, a preliminary study and exploration of the motor fault tree is carried out, and a method to construct a motor fault tree is proposed. The mathematics tools such as structural functions commonly used in fault tree analysis are described in detail. The three main methods of upsampling, downcasting, and Boolean cuts are introduced to analyze the algorithm of minimum cutsets. The three algorithms are illustrated by examples.

Firstly, the status quo of research at home and abroad and the significance of the research are analyzed. Then, the fault tree scheme for asynchronous motors is presented, and various types of faults that may occur in asynchronous motors are analyzed. The minimum cut sets are listed. In addition, the simulation of the fault tree of the asynchronous motor through matlab, more intuitive to reflect the possible causes of the motor failure, demonstrated the correctness of the results, and verified the application value of the fault tree analysis method. In the end, the graduation design was summarized, and the shortcomings and prospects were proposed.

Key Words:asynchronous motor fault; fault tree analysis; fault tree matlab simulation;