12 kV真空灭弧室绝缘结构电场分析及优化设计

Electric Field Analysis and Optimization Design of Insulation Structure of 12 kV Vacuum Interrupter

由于12 kV真空灭弧室工频电压老炼试验时,瓷壳内部出现局部击穿现象,需要对其内部结构进行研究,寻找一种改善灭弧室内部电位分布的绝缘优化方案。文中根据真空灭弧室的实际尺寸建立了三维电场计算模型,采用有限元计算得到了各部分的电场分布。对真空灭弧室的动静触头和屏蔽罩的绝缘强度进行了分析,根据其计算结果,对触头片边缘圆角、半径及其开槽宽度进行了优化,并对屏蔽罩的构造进行了改进,基于该优化方案进行电场分析,最后优化后的样机通过了工频电压老炼试验验证。

Due to the local breakdown phenomenon inside the porcelain shell during the power frequency voltage burn-in test of 12 kV vacuum interrupter,it is necessary to study its internal structure to find an insulation optimization solution to improve the internal potential distribution of the interrupter.In this paper,a three-dimensional electric field calculation model is set up based on the actual size of the vacuum interrupter,and the electric field distribution of each part is obtained by finite element calculation.The insulation strength of the moving and stationary contacts as well as the shield of the vacuum interrupter is analyzed.According to the calculation results,the edge fillet,radius and slot width of the contact piece are optimized and the structure of the shield is improved.The electric filed analysis is performed on the basis of the optimization scheme.Finally,the optimized prototype passed the power frequency voltage burn-in test verification.