隔离开关不完全合闸引起的电缆护层过电压分析  

Analysis of Cable Sheath Overvoltage Due to Not Completely Closing of GIS Disconnector

作　　者：张春霞[1,2] 孙伟忠[1,2] 屠幼萍[1,2] 陆宇航[3] 

机构地区：[1]华北电力大学高电压与电磁兼容北京市重点实验室,北京102206 [2]华北电力大学新能源电力系统国家重点实验室,北京102206 [3]北京电力公司,北京100023

出　　处：《高电压技术》2011年第10期2498-2505,共8页High Voltage Engineering

摘　　要：过电压威胁包括电缆在内的整个气体绝缘组合电器(GIS)系统的安全运行,而电缆护层的保护直接关系到供电质量,因此研究电缆护层上的过电压具有着重要的意义。为此基于ATP/EMTP电磁暂态仿真软件,以单相GIS隔离开关触头间弧光放电在电缆护层上感应出过电压为例,仿真分析了不同情况下的护层过电压。仿真结果表明,气隙击穿电压越高、熄弧时间越短造成的电缆护层过电压越严重。抑制电缆护层过电压最有效的方法是添加电缆护层保护器,但保护器在隔离开关气隙多次重燃下存在热崩溃问题。若交叉互联段上电缆本体相间外发生石墨电极放电,放电点处的护层过电压将明显降低,然而改变了护层保护器中的能量分布。研究发现,隔离开关的重复击穿将导致护层保护器损坏,使得石墨电极放电,引起护层保护器进一步被破坏。研究结果对电缆护层的过电压及其防护有参考价值。Taking the cable sheath overvoltage caused by an arc discharge fault in the operation of single-phase gas insulated switchgear（GIS） disconnector as an example, we numerically simulated the cable sheath overvohage under different eases. Simulation results show that, the higher the breakdown voltage of air gap is, and the shorter the arc cut-off time is, the moreserious the cable sheath overvoltage would be. Adding the sheath protector is the most ef- fective way to restrain the overvohage of the cable, however, the thermal capacity of the sheath protectors in the case of the arc reignition in GIS disconnector should be considered. If the graphite electrode outside the crossing connection of the cable discharges, the sheath voltage at the discharging point will decrease greatly, but the energy distribution of sheath protectors will change. It is found that arc reignition in GIS disconnector will cause the damage of sheath protector, resulting in graphite electrode discharging, and then more sheath protectors are destroyed further. The simulation results have reference values for the cable sheath overvoltage protection.

关 键 词：ATP/EMTP 气隙 GIS隔离开关 护层保护器 电缆护层 过电压 石墨电极 

分 类 号：TM595[电气工程—电器]