复合支柱绝缘子在长期载荷下的损伤识别方法

Damage Identification Method for Composite Post Insulator Under Long-term Load

复合材料在电气设备中的应用越来越广泛,其具有损伤隐蔽性的特点。复合材料设备受到长期环境荷载的作用之后,结构会累积不同程度的微小损伤且不易被发现。为了研究复合电气设备的损伤识别方法,以某200 kV复合支柱绝缘子为研究对象,首先分别进行不同损伤工况下的现场动力特性测试,得出不同工况下的频率变化;其次进行数值模拟,通过曲率模态差值分析和小波变换2种方法对绝缘子进行损伤识别;最后以曲率模态差为损伤指标得到该绝缘子的损伤曲线。研究表明:2种识别方法都可以有效地对绝缘子损伤位置进行识别,且小波变换的方法更为优越;损伤曲线可以通过曲率模态差较为准确地拟合损伤程度的大小。

Composite materials are widely used in the electrical equipment with the feature of damage invisibility.After being subjected to long-term environmental loads,the equipment is easy to produce undetectable micro structural damages.In order to identify the damages,one 200 kV composite post insulator was taken as the research object for field dynamic characteristic test under different damage conditions firstly,and the frequency changes under different conditions were obtained.Secondly,numerical simulation was carried out for damage identification of the insulator by using two methods of curvature modal difference analysis and wavelet transform.Finally,the damage curves of the insulator was derived by taking the curvature modal differences as the damage indicators.The study shows that both these two identification methods can effectively identify the insulator damage location,the wavelet transform method is more superior,and the damage curves can be more accurately fitted from the modal curvature differences to determine the size of damage degree.