110 kV棒形悬式复合绝缘子绝缘包覆均压环设计与试验研究

Design of 110 kV Composite Insulator Insulation Coated Grading Ring and Experimental Study

复合绝缘子安装均压环后减少了高压端和低压端的电弧距离,易受鸟害的影响,发生鸟粪闪络事故。为减少鸟害故障的发生,采用绝缘包覆的方法对普通均压环进行绝缘化改造,首先建立了三维仿真模型,分析了复合绝缘子电场分布规律,然后设计并制作绝缘均压环,通过模拟现场运行条件,测量了复合绝缘子周围的电场分布以及均压环周围放电情况,最后模拟了鸟粪闪络模拟试验,测试了绝缘包覆均压环电气绝缘性能。研究结果表明:绝缘包覆均压环与普通均压环的均压效果基本一致,绝缘包覆层对复合绝缘子沿面电场分布影响较小,对均压环周围的电晕放电影响也微乎其微。在同等条件下,还一定程度上减小绝缘子表面的最大场强。人工模拟鸟粪闪络试验表明,绝缘包覆均压环可以显著提高复合绝缘子的鸟粪闪络电压,从而降低鸟粪闪络发生的概率。

The composite insulator installed with grading ring can reduce the arc distance between high voltage side and low voltage side, while it is vulnerable to bird damage and the bird droppings flashover accident. In order to reduce the bird accident, the metal grading ring is insulated by insulation coating. 3 D simulation model is established to analyze the electric field distribution. The insulation grading ring has been designed and constructed. By simulating field operating conditions, the electric field distribution around the composite insulator and the discharge around the grading ring was measured. Finally, the simulation test of guano flashover was carried out by artificial simulation method, and the electrical insulation performance of the insulation coated voltage grading ring was tested. The results show that the voltage equalizing effect of the insulating coated pressure grading ring is basically the same as that of the ordinary metal pressure grading ring. The insulating coating has little influence on the electric field distribution along the surface of the composite insulator. It also has little effect on the corona discharge around the grading ring. Under the same conditions, the maximum field intensity on the surface of the insulator can be reduced to a certain extent. The simulated guano flashover test shows that the insulating coated grading ring can significantly improve the guano flashover voltage of composite insulators, so as to reduce the probability of guano flashover.