基于无人机红外测试的500kV架空线路在运复合绝缘子温度场特征分析

Temperature Characteristic Analysis of 500kV Transmission Line Composite Insulators Based on Field Infrared Test by Drone

为提升现场复合绝缘子红外测试判定准确率,对现场新投运的123支500 kV复合绝缘子开展基于无人机的红外测试,并提取复合绝缘子温度曲线,统计温差、温度梯度特征,对正常复合绝缘子自身不同部位温度差异的原因进行了讨论,并给出了抑制温度曲线高频干扰的方法。结果表明,现场正常复合绝缘子有相当比例温差超过2 K。正常复合绝缘子温度曲线存在高频变化分量,其来源于伞裙与芯棒之间的温差、红外图像清晰度不足产生的局部温度振荡。通过小波分解与低频分量重构,可有效抑制上述高频分量产生的温差,从而减小现场红外测试结果误判概率。

In order to improve the accuracy of infrared test judgment of field composite insulators,infrared tests based on drone are carried out on 500 kV composite insulators of new transmission lines. The temperature curve were attained,the characteristics of temperature difference and temperature gradient were counted. The reason for the temperature difference on different parts of the normal composite insulator is discussed,and the suppressing method of the high frequency interference of the temperature curve is given. The results show that considerable proportion of normal composite insulator is with temperature difference exceeding 2 K. The temperature curve of the normal composite insulator has a high-frequency variation component,which derived from the shed-rod temperature difference and the local temperature shock from lack of infrared image clarity. Through wavelet decomposition and compensation constant correction,the temperature difference caused by the high frequency components can be effectively suppressed,reducing the probability of field infrared test misjudgment.