瓷套式500kV氧化锌避雷器的电位分布计算及均压环设计

Calculation of Potential Distribution and Design of the Grading Rings for a New Type of Porcelain 500 kV Metal Oxide Arresters

采用有限元 解析结合解法 ,对 330kV和一种新型 5 0 0kV氧化锌避雷器 (MOA)电阻片的电压承担率进行了计算 ,解决了含复杂介质和导体结构的轴对称无界电场的数值计算问题 ,其程序设计与通用的有限元法完全相似 .在 330kVMOA的计算结果与实测结果取得了良好一致性的基础上 ,分析了影响新型结构 5 0 0kVMOA电阻片的电压承担率的多种因素 ,并给出了电阻片的电压承担率分布较为合理的一种结构设计方案 .

A hybrid FEM-analysis is presented for the calculations of voltage distribution ratios of the zinc-oxide elements of 330 kV and a new type of 500 kV metal oxide arresters (MOA). The procedure is based on region division in which finite region and infinite region are evaluated by finite element analysis and eigenfunction expansion respectively. This hybrid method gives a way out of the difficulties in the numerical computations of axisymmetrical open-boundary electrostatic fields with complicated media and arbitrary configuration conductors, and is very similar to the normal FEM in computer program. An experiment on 330 kV MOA were performed to show the accuracy of the procedure. The experimental results are in close agreement with the values predicted by the analysis. Many factors affecting the voltage distribution ratios of 500 kV MOA have been put forth. Finally,an optimal design of zinc-oxide elements is proposed.