1000kV交流复合绝缘子串电场分布计算及均压环设计

Electric Field Distribution Calculation and Grading Rings Design of 1000kV AC Composite Insulator

1 000kV复合绝缘子的结构特点导致了其电位分布很不均匀,高压端金具附近的强场区会使绝缘介质和金具表面发生电晕放电,如何设计均压环使绝缘子沿面电场分布得到改善,对输电线路的安全运行具有重要的意义。本文基于ANSYS有限元软件建立1 000kV复合绝缘子的三维模型,计算无均压环时和有均压环时的复合绝缘子沿面电场强度分布和电压分布,具体分析了大小均压环的位置、环径、管径对复合绝缘子沿面电场强度的影响,并确定均压环的最佳位置和结构参数。计算结果表明,有均压环时均压环表面,高压端金具表面及绝缘护套表面的最大场强均可达到要求。

The structural characteristics of 1 000kV composite insulator result the high non-uniform of the potential distribution,so the high electric field area near the high-voltage terminal of metal fitting will generate corona discharge on the surface of insulating medium and metal fitting.To improve electric field distribution by designing grading ring has important significance for the operation security of transmission lines.In this paper,ANSYS finite element software is used to establish a 3-D model of 1 000kV composite insulator,the electric field intensity distribution and voltage distribution on the surface of the composite insulator are calculated in cases of insulator with and without grading ring.The influences of position,ring radius and radius of the ring tube of the big and small grading ring on electric field intensity on the surface of composite insulator are analyzed,and the optimal position and structure parameters of grading ring are determined.The calculation results show that the maximum electric field intensity on the surface of grading ring,metal fitting at high voltage terminal and the insulator protection sheath will meet the requirements.