特高压交流复合绝缘子电位和均压环表面电场分布计算

Potential Distribution Along UHV AC Transmission Line Composite Insulator and Electric Field Distribution on the Surface of Grading Ring

针对特高压交流线路复合绝缘子电位、电场分布数值分析存在开域边界、几何结构复杂和媒质种类多、计算量大等问题,通过等效有限元法将有限元求解区域与边界元求解区域的交界面条件耦合,实现了有限元—边界元耦合算法(FEM-BEM)。将三维FEM-BEM和子域逼近有限元算法用于计算特高压交流线路典型酒杯塔,复合绝缘子双I串的沿轴线电位分布,均压环表面电场分布。研究表明:三维FEM-BEM耦合算法能有效计算复合绝缘子沿轴线的电位分布,子域逼近有限元法能对所关心区域进行细密剖分,可有效分析均压环表面电场分布;复合绝缘子沿轴线承担最大电压单元(一大一中两小伞及芯棒)为第3单元,承担电压为7.58%,均压环典型路径上的电场强度最大值为13.39kV/cm;将三维FEM-BEM耦合算法与子域逼近有限元法相结合,为准确求解复杂几何模型和多种媒质共存的开域静电场问题提供了一条途径。

The coupling finite element method and boundary element method （FEM-BEM） method and sub-region approximation FEM were proposed together to solve the potential distribution of 1000 kV AC cup-shaped tower,composite insulator double I string and electric field distribution on the surface of grading ring.The research results indicate that,the three-dimensional FEM-BEM can effectively calculate the potential distribution along the axis of UHV composite insulator with infinite open boundary,sub-region approximation FEM can accurately analyze the electric field distribution on the surface of the grading ring by sub-region approximation the interest regions step by step and with fine mesh.The maximum withstand voltage percentage along the insulator of double I string are on the No.3 unit,and the value is 7.58%.The maximum electric field intensity of the typical path on the surface of the grading ring is 13.39 kV/cm.The FEM-BEM and sub-region approximation FEM supply a method to accurately analyze the electrostatic field problems with complex geometry structure,with multi medium,infinite open boundary and large calculation scale.