Creeping Discharge Phenomena along Aerial Insulated Wire

在高压架空配电系统中，架空绝缘导线由电线杆上的绝缘子和绑扎线支撑。当雷击发生在他们附近时，雷击浪涌侵入电线的中心线。雷电浪涌引起绝缘子闪络时，沿导线表面产生蠕变放电。然后，电线暴露在电线熔化失效的危险中。为了防止这种事故的发生，对蠕变放电的解释是非常重要的。研究了在峰值Vm=±90、±100kV、波前持续时间Tf=1.2 ~ 100.0μ s的脉冲电压作用下，沿导线表面产生的蠕变放电特性。现澄清如下。(1)展开长度展开长度不受波前持续时间Tf=1.2 ~ 8.0μs的影响。波前持续时间Tf=10.0 ~ 100.0 μs时，波前持续时间越长，发展长度越短。(2)外形：沿线材表面发展，不受Tf和vm的影响。负蠕变放电：(1)显影长度在Tf=1.2 ~ 20μs范围内，随着Vm的增加，显影长度出现增减区。在Tf=50和100μs范围内，长度随Vm的增加而单调增加。而随着Tf的增大，发育长度呈抑制趋势。(2)方面Vm≦100 kV时，放电尖端出现的离散跳变现象随着Tf的增大而受到抑制。明确了负蠕变放电时，放电尖端跳变现象的减小使发展长度变长。

In high voltage aerial distribution systems, the aerial insulated wires are supported by the insulators and the binding wires at the electric light poles. When the lightning strike occurs in their neighborhood, a lightning surge invades to the central line of wire. If the flashover of insulator happens by the lightning surge, the creeping discharge can develop along the wire surface. Then, the wires are exposed to danger of the wire melting failure. In order to prevent this accident, the elucidation of the creeping discharge is very important.We investigated the property of creeping discharge which develops along the wire surface under the impulse voltage application with peak values Vm=±90, ±100kV and duration of wave fronts Tf=1.2-100.0μS. It has been clarified as follows.1. Positive ceeping discharge :(1)Developing length The developing length does not influenced by the duration of wave front Tf=1.2-8.0μs. At durations of wave front Tf=10.0-100.0 μs, the developing length becomes short when the duration of wave front becomes long. (2)Aspect It develops along the wire surface with jumping independent of Tf and Vm.2. Negative creeping discharge :(1)Developing length The increase and decrease regions of the developing length appears with the increase of Vm in Tf=1.2-20μs. The length increases monotonously with the increase of Vm in Tf=50 and 100μs. However, the developing length shows a restrained tendency with the increase of Tf. (2)Aspect The discrete jump phenomenon which occurs at the discharge tip in Vm≦100 kV is restrained with the increase of Tf. It was clarified that the decline of the jump phenomenon at the discharge tip in the negative creeping discharge made a developing length long.