10 kV配网过电压绝缘子传感器结构设计及电场仿真研究

Structure Design and Electric Field Simulation of Over-voltage Insulator Sensor in 10 kV Distribution Network

针对配变台区的过电压监测问题,以线路中广泛使用的绝缘子为研究对象,通过在内部增设高压陶瓷电容,在不降低设备绝缘性能的条件下实现了故障信号的有效提取。首先基于故障信号特征及后端处理需求,确定检测装置分压比为500∶1;然后搭建了PSCAD线路模型,对雷电冲击过电压下测量结果开展仿真,得到高低压臂电容最优参数为400 pF、200 nF。在此基础上,结合电容器常规参数确定了组接方式及内部尺寸,并根据工程需求及国标要求确定了电极、柱体、伞裙等主体结构参数。完成整体设计后,按照模具1∶1比例搭建了三维有限元模型并进行电场及电势仿真分析,未出现局部电场畸变或电势过于集中等缺陷。该装置有效利用了绝缘子的内部空间,尺寸较小,稳定性强,适用于配网中大规模、分布式测量。

To achieve overvoltage monitoring in the distribution network,the widely used insulators in transmission lines is taken as the research object.The overvoltage signal is effectively extracted without reducing the insulation performance of the equipment by adding high voltage ceramic capacitors inside the insulator.Considering the characteristics and back-end processing requirements of the fault signal,the partial voltage ratio of the detection device is determined to be 500∶1.Furthermore,the PSCAD line model is built,and the measurement results under lightning impulse overvoltage are simulated.The analysis shows that the optimal parameters of high and low voltage arm capacitance are 400 pF and 200 nF.Then the insulator′s internal size and connection mode are determined according to the conventional parameters of capacitors.The main structure parameters,including electrodes,column,and umbrella skirts,are designed based on engineering requirements and national standards.The 3-D finite element model is built according to the 1∶1 ratio of the mold to analyze the electric field and potential distribution characteristics.The device effectively utilizes the internal space of the insulator,has a small size and strong stability,and is suitable for large-scale and distributed measurement in a distribution network.