两种材料绝缘护套对输电线路空气间隙击穿特性影响研究

Effects of Two Insulating Material Sheaths on Air Gap Breakdown Characteristics of Power Transmission Line

近年来,受大风条件影响,架空输电线路导线对杆塔及周边障碍物放电情况日益严重,为研究两种材料绝缘护套包覆对以上问题的防治效果,在5~40 cm间隙距离内,对裸导线、单/双导线包覆聚烯烃与硅橡胶绝缘护套情况下进行导线间空气间隙工频击穿试验。结果表明:裸导线间工频击穿电压与间隙距离近似呈线性关系,导线包覆绝缘护套可有效提高输电线路导线间空气间隙的击穿电压。在5~40 cm间隙距离下,双线包覆绝缘护套时的击穿电压提升效果远大于单线包覆,聚烯烃热缩套管对击穿电压的提升效果整体优于硅橡胶护套。在双线包覆时,聚烯烃包覆时击穿电压最大提高189.77%,最小提高20.98%;硅橡胶护套包覆时,击穿电压最大提高101.32%,最小提高25.50%。相近厚度的交联聚烯烃护套较橡胶绝缘护套更具经济性,且使用效果更佳。

In recent years, the dsicharge problems between conductor and tower or surrounding obstacles in overhead transmission lines affected by wind condition are getting seriously. In order to study the preventing effect of two insulating material sheaths on the problems above, power frequency breakdown tests of air gap between conductors were conducted on bare conductor, single-conductor and double-con- ductor covered by polyolefin and silicone rubber insulating sheaths, and the gap distance ranged from 5 cm to 40 cm. The results show that the breakdown voltage of bare conductor has a linear relationship with gap distance, and the insulating sheath can effectively improve the breakdown voltage of air gap between lines. When the gap distance ranges from 5 cm to 40 cm, the breakdown voltage of double-con- ductor covered by insulating sheath is much greater than that of single-conductor, and the breakdown voltage of conductor covered by polyolefin insulating sheath is entirely higer than that of conductor covered by silicone rubber insulating sheath. The breakdown voltage of double-conductor increases by at least 20.98% and at most 189.77% when it covered by polyolefin insulating sheath, while the breakdown voltage increases by at least 25.5% and at most 101.32% when it covered by silicone rubber insulating sheath. The polyolefin insulating sheath with similar thickness has more economic advantages and better effect than silicone rubber insulating sheath.