750kV线路绝缘子串电压分布的有限元计算

CALCULATION OF VOLTAGE DISTRIBUTION ALONG INSULATOR STRINGS OF 750kV BY FINITE ELEMENT METHOD

特高压架空输电线路绝缘子串的电压分布对于绝缘子的相关设计和运行维护非常重要。运用静态电场的三维有限元法分析计算了750kV输电线绝缘子串的电压分布,考虑了绝缘子电介质、屏蔽环、输电线路及铁塔对绝缘子电压分布的影响;比较了计算结果与实测值,并分析了误差产生的原因。根据计算结果建议对于玻璃绝缘子串加屏蔽环以减少第1片绝缘子承受的电压百分比。运用三维有限元法计算高压绝缘子串中的电压分布是可行且有效的,可应用于更为复杂条件下的绝缘子串电场分布的计算分析。

It is very important for the related design, operation and maintenance of insulators to measure the voltage distribution along insulator strings of 750kV overhead transmission line. Using 3-dimension finite element method (FEM) for static state electrical field, the voltage distribution along insulator strings of 750kV overhead transmission line is analyzed and calculated, while the influences of dieletric of insulator, shielding ring, transmission line and transmission tower on voltage distribution along the string are considered. The calculation results and the measured results are compared and the reasons causing the error are analyzed. According to the calculation results it is suggested that adding shielding ring to glass insulator strings to reduce the voltage percentage bearing by the first piece of insulator. It is feasible and effective to apply 3-dimesion FEM to the calculation of voltage distribution along the insulator strings in high voltage transmission line, and this method can be used to the calcualtion and analysis of the voltage distribution along the insulator strings under more complicated conditions.