输电线路导线安装绝缘护套的研究

Study on Installation of Insulation Sheath for Transmission Line

针对强风导致紧凑型输电线路各相导线间间隙距离减小而发生的闪络情况,分别采用了辐射交联聚烯烃材料的母排热缩管和优质硅橡胶材料的卡扣式绝缘护套管,提出了将其安装在输电线路上来进一步增大输电线路相间放电距离的方法。建立了模拟输电线路风偏放电试验的物理模型,在不同间距情况下,对裸电线和裸导线分别双根包覆绝缘护套进行导线间空气间隙工频击穿试验。试验结果表明:裸导线空气间隙工频击穿电压与间隙距离近似呈线性关系,这与棒-棒间隙相似。裸导线双根包覆不同绝缘护套后,击穿电压提升都很明显,但卡扣式硅橡胶管安装更为方便,母排热缩管可考虑在杆塔跳线段使用,防止跳线在大风条件下对杆塔放电。利用COM-SOL软件从场强的角度上分析了安装绝缘护套对裸导线空气间隙工频击穿电压提升的原理,证实了该方法的适用性和有效性。

The gap distance between each phase conductor of compact type transmission lines is re- duced in the gale, which may Iead to the flashover. Aim at this situation, it is proposed that the discharge distance of transmission line can be increased by installing two insulation sheaths on the transmission line separately, radiation crosslinked polyolefin heat shrink tube and high quality silicone rubber button insulation sheath. The physical model that simulates the windage yaw discharge of transmission lines is built, and power frequency breakdown test of the air gap between the transmissions is carried out under different distances in the case of bare wires and bare wires respectively double-coated insulation sheath. The test result shows that the relationship of power frequency breakdown voltage of the bare wire air gap and gap distance is approximately linear, which is similar to rod-rod clearance. The increase of break- down voltage is evident with bare wire respectively double-coated insulation sheath, but the installment of button insulation sheath is more convenient, and heat shrink tube can be used in the tower jumper line segment to prevent the discharge of the tower and wire in the gale. The principle that installing insulation sheath can improve power frequency breakdown voltage of the bare wire air gap is analyzed from the field perspective by using COMSOL software, which confirms the method is applicable and effective.