基于光电电场传感器的复合绝缘子内部绝缘故障检测

Detection of Internal Insulation Defects of Composite Insulator Based on Electro-optic Electric Field Sensor

为提高电场分布法检测复合绝缘子内部故障的灵敏度,基于光电集成电场传感器搭建了一套用于复合绝缘子内部故障检测的实验系统。使用该系统模拟进行绝缘子故障检测,得到了绝缘子附近的电场分布曲线,验证了其检测绝缘子短路故障的可行性。然后对老化实验所得绝缘子和现场运行过的绝缘子进行了故障检测实验,结果表明:绝缘子表面附近轴向电场分布的测量点位于距离伞群边缘10 mm(外侧)时,内部绝缘故障检测具有最佳灵敏度,此时传感器可测量出的最小短路故障为长20 mm的短路故障。

To promote the detection sensitivity of the electric field mapping method, we set up an experimental system based on electro-optic electric field sensors for the defect detection of composite insulator. Then we performed simulative defect detection experiments and got the axial electric field distribution with depression near the sheds along the insula- tors so as to prove the validity of the proposed method. We also tested some insulators obtained from ageing experiments and field operation. The results show that, for internal insulation defects detection, optimal sensitivity can be obtained when the measurement points of the axial electric field distribution around the insulator are 10 rnm far from the edge of the insulator sheds （outward）, and the smallest defect that can be detected by the sensor is 20 mm long short circuit.