550kV隔离开关静触头电场数值计算与均压环设计

Numerical Calculation of Electric Field and Design of Grading Ring for Fixed Contact of 550 kV Disconnector

550 kV高压隔离开关钳夹式静触头结构复杂导致电晕现象严重。为了解其表面电场分布并提出改进方案,文中首先计算了无防电晕结构下三维电场分布,得出绞线圈、下夹块、静触杆端部等高场强区域,继而针对此提出在夹块处各安装小均压盘与安装双大均压环的防电晕结构方案,并通过仿真计算对两种方案进行比较。小均压盘几何参数对静触头电场的影响结果表明,小均压盘对抑制绞线圈表面起晕作用不明显,对静触头电场屏蔽能力有限。双均压环静触头电场计算结果表明,该结构屏蔽范围广,屏蔽效果更为理想。双均压环静触头GW16A-550型高压隔离开关无线电干扰试验结果,进一步证明双均压环结构较小均压盘方案更为优越,是550 kV电压等级下最理想方案。文中分析结果,对高压隔离开关静触头防电晕结构设计提供理论依据。

The complex structure of fixed clamping contact of the 550 kV high-voltage disconnector leads to serious corona. For understanding the electric field distribution around the contact surfaces and putting forward optimization proposals, the 3-D electric field distribution of the model without grading ring was calculated in this study, and the result showed that the strand wire circles, the lower clamp and the heads of static contact rod are the areas where electric field intensity is higher. In consequence, two anticorona contact structures were proposed, in which a small disc-type grading ring and a double large grading ring were installed to each of four clamps, respectively. And the two structures were compared via simulation. The simulation revealed that the small disc-type grading ring with different geometrical parameters exerts little effect on corona on surface of the strand wire circles, and its shielding effect is limited, while the structure with double grading rings has a larger shielding area and better shielding effect. Radio interference test of a GW16A-550 high-voltage disconnector with double grading rings on its contact was completed, the results show that the structure of the fixed contact with double grading rings is better than the other at 550 kV voltage level. This study may provide a theoretical reference for anticorona structure design of fixed contact of high-voltage disconnector.