110kV劣化瓷质悬式绝缘子空间电场研究

输电线路运行的绝缘子发生劣化时,其周围空间电场相对正常状态会发生局部畸变,因此比较和分析绝缘子劣化前后的电场分布特性,可以识别出劣化绝缘子。文章通过有限元仿真软件建立110 k V瓷质悬式绝缘子的1:1有限元电场仿真模型,得到绝缘子串性能良好时的电场分布参考曲线;通过改变绝缘子串劣化位置和程度,获得劣化状态下绝缘子串的空间电场分布变化曲线。仿真结果表明:绝缘子串劣化区域的轴向电场强度显著降低,其中零值绝缘子比低值绝缘子的下降程度更为突出;另外随着测量距离的增大,劣化绝缘子造成的电场畸变逐渐减弱。在高压实验大厅搭建绝缘子空间电场实验平台,用光学电场传感器测量了绝缘子串在不同情况下的轴向电场并通过"直线归一法"对测量数据进行了处理,试验结果表明:劣化绝缘子附近的轴向电场显著减小,与仿真结果一致。因此,测量空间电场可以实现劣化绝缘子的带电检测。

Study on space electric field of 110kV faulty porcelain suspension insulator

When insulators in the transmission line are faulty, the electric field around them will be partially distorted compared to the good insulator strings. Therefore, the electric field distribution characteristics before and after the fault can be compared to recognize the faulty insulators. In this paper, a 1:1 model of 110kV porcelain insulators based on finite element method is established. and the electric field distribution around insulator strings is calculated without a faulty insulator. By changing the different position and degree of faulty insulator, electric field distribution curve around faulty insulator strings is obtained. The simulation results show that axial electric field around faulty insulator decreases and electric field intensity around the zero-value insulator is smaller than low-value insulator. The farther the measurement distance is, the less the distortion of the electric field curve is. Insulators electric field test platform was built in high-voltage experiment hall. The axial electric field of insulator is measured by electric field sensor and the data were processed by "linear normalization method". The test results show that the electric field around low value and zero value insulator apparently decreases, which is agreement with results of simulation, to verify the effectiveness of the changes of the electric field. Therefore, the measurement of space electric field can realize live detection of faulty insulators.