特高压GIS中隔离开关的电场及参数计算

Electric Field Numerical Analysis and Parameter Calculation of Ultra-high Voltage GIS Disconnector

为获得1100kV气体绝缘变电站(GIS)中隔离开关的电场分布规律及相关参数,利用有限元软件对其气室进行了三维电场分析计算,得到了其内部电场强度分布和不同电极表面电场强度分布曲线。分析电场强度结果得出了隔离开关气室内电场强度较大的位置及电场强度值;分析接地开关静触头直径与边倒角尺寸对触头表面附近的电场分布影响从而降低了触头表面场强以提高耐压能力。利用参数化设计语言(APDL)和电场能量法计算电容参数得出的气室内不同位置电容与测试结果比较,两者相对误差<4%,证明利用电场能量法可以获得较为准确的分布电容值,进而为特高压GIS中快速暂态过电压(VFTO)的计算提供了比较准确的分布电容参数。

Three dimension electric field of 1100 kV SF6 disconnector cabinet is analyzed and calculated to acquire the distributions of electric field intensity and the curves of electric field intensity distributions in different electrode surfaces by using the finite element software. The positions of higher intensity and their intensity values are obtained by analyzing the results. The effects on the electric field distribution near the surface of contact caused by change of dimensions of earthing switch static contact diameter and boundary chamfer are analyzed so as to reduce the surface electric field intensity of contact and to improve the ability of pressure resistance. The capacitance parameters are cal- culated by using the ANSYS parametric design language （APDL） and electric field energy method, then the calculation results of capacitance in different positions of disconnector cabinet are acquired, and the calculation results of capacitance parameters are compared with the test results of capacitance parameters, the relative errors of capacitance calculation results are less than 4% in different positions of disconnector cabinet. Therefore, the capacitance values which are calculated by electric field energy method are more approximate to the true values, then the more accurate capacitance parameters can also be provided for the calculation of very fast transient over-voltage（ VFTO）in ultrahigh voltage GIS.