基于导波的大电机定子绝缘损伤定位仿真研究

Simulation Study on Damage Localization of Large Generator Stator Insulation Based on Guided Waves

提出了一种基于导波的大电机定子绝缘损伤定位方法。通过求解Rayleigh-Lamb频率方程获取导波在定子绝缘中的频散曲线。利用Abaqus有限元分析软件建立了横向裂纹,纵向裂纹、气隙和分层4种典型定子绝缘结构损伤模型,对导波在定子绝缘结构中的激励、接收和传播特性进行了数值模拟。在此基础上,采用小波尺度谱提取损伤散射信号飞行时间确定损伤位置,对不同模态下的导波损伤定位精度进行了分析。仿真结果和理论分析说明了本文方法的损伤定位精度。

A stator insulation damage localization method based on guided waves was proposed. The dispersive curve was obtained by solving the Rayleigh-Lamb equations. Finite structure models of four typical groundwall insulation damage, i.e. void, delamination, longitudinal and transverse crack were established by FEM software Abaqus, in which the excitation, acquisition and propagation properties of guided wave were numerical simulated. Based on that, wavelet scalogram was used to extract the flight time of damage-scattered wave to obtain the insulation damage location. Analysis was conducted to compare the location precision under each wave modes. Simulation results indicate that the method is effective to locate insulation damage with a high precision.