振荡冲击电压下SF_6极不均匀场间隙的放电特性

根据IEC 60060-3所规定的振荡冲击电压波形,研究了在正极性振荡雷电冲击电压和振荡操作冲击电压下SF6气体极不均匀场间隙的放电特性,包括SF6压强(P)和50%起晕电压(UP50)关系、SF6压强(P)和50%击穿电压(UB50)关系等。并且比较了振荡雷电冲击和标准波雷电冲击下SF6气体极不均匀场间隙的放电特性的异同。结果表明,振荡型冲击电压因其振荡特性,使SF6极不均匀场间隙的放电次数增加,这有利用发现GIS中存在的例如导电尖刺等电极缺陷;等波头的振荡冲击波和双指数冲击波作用下SF6极不均匀场间隙的有着相似的放电特性,这对振荡型冲击波替代双指数波在较高等级的GIS现场耐压试验中的运用有重要的指导意义。

Discharge Characteristics of SF6 Non-uniform Field Gap under Oscillating Impulses

Based on the IEC 60060-3 about oscillating impulse voltage waveforms,this paper studies the discharge characteristics of SF6 non-uniform field gap under positive polarity oscillating lightning impulse and oscillating switching impulse,which includes the relationship between the pressure of SF6(P) and 50% inception corona voltage(UP50),and the relationship between the pressure of SF6(P) and 50% breakdown voltage(UB50).The paper compares the discharge characteristics of SF6 non-uniform field gap under the oscillating impulse and the standard impulse.The results show that the discharge number increases because of oscillating so that it is better to reflect defective electrode like the conductive spiked of GIS;The partial discharge characteristics of SF6 non-uniform field gap are similar under the same wave-front double exponential impulse and oscillating impulse.It has important significance to guide the high voltage GIS on-site testing under the oscillating impulse replacement double exponential impulse.