复合绝缘子表面异常发热点识别方法  

Method for Identifying Abnormal Hot Spots on the Surface of Composite Insulators

作　　者：刘垚 LIU Yao(State Grid Ningxia Electric Power Co.,Ltd.,Yinchuan 750000,China)

机构地区：[1]国网宁夏电力有限公司,银川750000

出　　处：《光通信研究》2024年第6期38-43,共6页Study on Optical Communications

摘　　要：【目的】为了避免复合绝缘子热故障造成的高压输电线路运行风险,文章研究了复合绝缘子表面异常发热点识别的方法。【方法】文章分析了电流发热型、电压发热型以及综合发热型3种复合绝缘子表面异常发热形式,基于分析结果,利用光纤光栅集中测温技术,将光纤光栅传感器布设于复合绝缘子附近,采用光纤光栅集中测温单元计算相应波长偏移量及温度变化值,将变化值经数字信号处理单元解析后,生成复合绝缘子热图像。之后,文章使用最大类间方差法分割复合绝缘子热图像,计算复合绝缘子热图像的平均灰度,获取最优阈值划分复合绝缘子热图像中的像素。根据复合绝缘子热图像分割结果,利用像素统计方法,统计复合绝缘子分割图像横向的行像素点,划分复合绝缘子结构区域。依据带电设备热图像诊断应用规范,结合光纤光栅集中测温原理,将光纤光栅传感器采集的复合绝缘子热图像以伪彩色呈现复合绝缘子表面温度分布情况。最后,通过目标图像各结构区域间的温度关系,实现复合绝缘子表面异常发热点的识别。【结果】实验结果表明,该方法能够准确测量复合绝缘子表面任意点温度,最大均方根误差仅为1.39%;能有效划分复合绝缘子分割图像的结构区域,各结构之间分界明显,不存在重合现象。【结论】使用文章所提方法识别高压输电线路上不同区域的复合绝缘子表面异常发热点的性能均较为理想,复合绝缘子结构区域划分效果较为优良。【Objective】To avoid the operational risk of high-voltage transmission lines caused by thermal faults of composite insulators,a method for identifying abnormal hot spots on the surface of composite insulators is studied.【Methods】Three types of abnormal surface heating forms of composite insulators,current heating type,voltage heating type,and comprehensive heating type,are analyzed.Based on the analysis results,the fiber Bragg grating centralized temperature measurement technology is used to deploy the fiber Bragg grating sensor near the composite insulator.The fiber optic dispersion centralized temperature measurement unit is used to calculate the corresponding wavelength offset and temperature change value.After being analyzed by the digital signal processing unit,the thermal image of the composite insulator is generated.Using the maximum inter class variance method to segment the thermal image of composite insulators,the average gray level of the thermal image of composite insulators is calculated,and the optimal threshold to partition the pixels in the thermal image of composite insulators is obtained.Based on the thermal image segmentation results of composite insulators,pixel statistical methods are used to calculate the horizontal row pixel points of the composite insulator segmentation image and divide the structural area of the composite insulator.According to the application specification of thermal image diagnosis for live equipment and the principle of fiber grating centralized temperature measurement,the thermal image of composite insulator collected by the fiber grating sensor is displayed in pseudo color to show the surface temperature distribution of composite insulator.The abnormal hot spots on the surface of composite insulators are identified through the temperature relationship among various structural regions of the target image.【Results】The experimental results show that this method can accurately measure the temperature of any point on the surface of composite insulators,and the

关 键 词：光纤光栅 集中测温 复合绝缘子 异常发热点 最大类间方差 像素统计 

分 类 号：TM930[电气工程—电力电子与电力传动]