绝缘护套对间隙交流击穿特性的影响研究

Research on Influence of Insulating Sheath on AC Breakdown Characteristics of Gap

在架空输电线路上包覆绝缘护套是工程中常用的防鸟害措施之一,鸟粪与护套表面之间空气间隙的击穿电压直接影响护套的配置方案。本文采用铜棒模拟鸟粪,通过试验研究了不同空气间隙距离下,击穿电压随护套厚度的变化特性以及护套缺陷对击穿电压的影响。结果表明:与不包覆护套的裸导线相比,包覆厚度为2.0、3.0、3.5 mm护套的导线,间隙击穿电压可分别提高17.7%、33.1%、41.6%;与相同厚度的全新护套相比,存在击穿点且厚度为2.0、3.0、3.5 mm的护套,间隙击穿电压分别降低了70.6%、62.8%、44.2%,说明有击穿点的护套厚度越小,击穿电压降低幅度越大。

Covering insulating sheath on transmission lines is one of the commonly measures to prevent bird damage in engineering,and the breakdown voltage of the air gap between bird droppings and the surface of sheath directly affects the configuration scheme of sheath.In this paper,the variation characteristics of breakdown voltage with the thickness of sheath and the influence of sheath defect on the breakdown voltage under different air gap distance were investigated by experiment,in which the bird droppings were simulated by copper rod.The results show that compared with bare wires,the breakdown voltage of the gap in the wires covered sheath with the thickness of 2.0,3.0,3.5 mm increases by 17.7%,33.1%,41.6%,respectively.Compared with new sheath of the same thickness,the breakdown voltage of gap in the defective sheath with the thicknesses of 2.0,3.0,3.5 mm decreases by 70.6%,62.8%,44.2%,respectively.It is concluded that the smaller the thickness of the defective sheath,the larger the decreasing amplitude of breakdown voltage.