大电机定子绝缘损伤成像检测方法研究.pdf

第35 卷 第5 期 噪 声 与 振 动 控 制 Vol 35 No.5 2015 年10 月 NOISE AND VIBRATION CONTROL Oct. 2015 文章编号：1006-1355(2015)05-0193-05 大电机定子绝缘损伤成像检测方法研究 李 豪，李锐华，胡 波，潘 玲，郭其一 （同济大学 电子与信息工程学院，上海 201804 ） 摘 要：为了准确评估定子绝缘结构健康状况，基于导波理论进行定子绝缘结构损伤成像检测研究。首先根据定 子绝缘材料特性参数，建立定子线棒结构有限元模型。对定子绝缘损伤检测中导波的激励、传播和接收进行数值模 拟，并建立横向裂纹、纵向裂纹、气隙和分层四种典型定子绝缘损伤模型。利用希尔伯特变换提取损伤散射信号到达 时间作为损伤特征，采用概率成像方法对定子绝缘中的损伤状况进行成像检测。数值仿真结果表明：损伤散射导波飞 行时间是表征损伤位置的有效特征，A0 模态损伤散射波对定子绝缘损伤更敏感，概率成像能够直观地检测出定子绝缘 中的损伤并能进行准确定位，为进一步应用导波进行大电机定子绝缘状态评估提供有效的参考信息。 关键词：振动与波；定子绝缘；状态评估；损伤检测；弹性导波；概率成像 中图分类号：TM3 文献标识码：A DOI 编码：10.3969/j.issn.1006-1335.2015.05.041 Damage Detection of Large Generator Stator Insulation Using Guided Wave-based Imaging Method LI Hao , LI Rui-hua , HU Bo , PAN Ling , GUO Qi-yi ( School of Electronics and Information Engineering, Tongji University, Shanghai 201804, China ) Abstract : In order to accurately assess the health condition of stator insulations, the basic theory of guided- wave and probability- imaging method was employed for stator insulation damage detection of large generators. The excitation, propagation and acquisition of the guided wave for the stator insulation damage detection were simulated numerically. Finite element models of four typical insulation damages, i.e. void, delamination, longitudinal and transverse cracks were established. Hilbert Transform (HT) was used to extract the time of flight (ToF) of damage scattered wave as the damage feature for damage location detection. Then, the probability-imaging method was used to detect the damage situation of the stator insulation. Numerical simulation results reveal that the