摘要
Both the ceramic and the composite insulators have their own advantages and disadvantages when compared with each other. It is a reasonable idea to combine their merits together to design a novel insulator. The key measure of the novel insulator suggested in this paper is to add an annular metal sheet coated with high temperature vulcanisation (HTV) silicone rubber (SIR) at the base of the traditional ceramic insulator cap. The HTVSIR covering on the exterior of the metal sheet can lengthen the creepage distance. The metal sheet can uniform the electric stress, reduce its maximum value and modify its direction on one insulator unit and acts as equalizing ring on an insulator string. The factors stated above are the main reasons why the novel insulator has better insulating performance, including lower leakage current and flashover voltage, especially under polluted conditions. Simultaneously, the novel insulator can overcome the disadvantages of the ordinary remedies which have been widely used to improve the performance of ceramic insulators against pollution. The experimental results obtained in the laboratory were in good agreement with the theoretical analysis and demonstrated the novel insulator's effectiveness.
以普通瓷质绝缘子为基础 ,并充分利用硅橡胶材料优良的防污性能 ,提出了一种新型绝缘子的设计方法 ,其主要措施是在普通瓷质绝缘子的铁帽中部加装了一个表面被覆高温硫化硅橡胶 (HTVSIR)的金属环片 .金属环片表面的HTVSIR可以达到增加爬距和防污的目的 ,金属环片本身除支撑HTVSIR外 ,还可以改变电场分布以抑制放电的发展 ,从而提高新型绝缘子的起晕和放电电压 .清洁和污秽两种情况下的实验结果证明了新型绝缘子确实可以有效地减少表面泄漏和显著地提高闪络电压 .
