输电线路绝缘子表面局部放电紫外图像检测方法

UV Image Detection Method for Partial Discharge on Insulator Surface of Transmission Line

在电、热、力以及物理环境因素长期作用的影响下,电力设备绝缘电气、机械及其他性能下降会引起设备老化、破损等现象,影响电力设备的安全稳定运行。目前,紫外检测技术可应用于检测电力设备绝缘表面的早期局部放电现象,检测到的光子数结果受背景噪声影响较大。为了准确评估输电线路绝缘子表面局部放电强度,基于电力设备绝缘表面局部放电图像特征和紫外成像检测原理,采用阈值法和形态学滤波相结合的放电光斑面积计算方法,并通过玻璃绝缘子的局部放电试验对该计算方法进行验证。实验结果表明:随着外施工频电压幅值的增大,玻璃绝缘子表面放电紫外光子数均值增大,放电光斑面积也随之增大,验证了所提局部放电光斑面积计算方法的合理性。

Under the long⁃term influence of electrical,thermal,mechanical and physical environmental factors,the electrical,mechanical and other performance of power equipment insulation will decline,and there will be aging,damage and other phenomena,which affect the safe and stable operation of power equipment.At present,ultraviolet(UV)detection technology can be applied to detect the early partial discharge of power equipment insulation,and the number of photons detected is greatly affected by the background noise.In order to accurately assess the partial discharge intensity on the insulator surface of transmission line,a method for calculating the discharge spot area was proposed by combining the threshold method and morphological filtering based on the image characteristics of partial discharge on the insulation surface of power equipment and the principle of UV imaging detection.The calculation method was verified by partial discharge test of glass insulator.The experimental results show that with the increase of the external frequency voltage amplitude,the average number of UV photons on the surface of the glass insulator increases,and the area of the discharge spot also increases,which verifies the correctness of the proposed method.