摘要
开关柜内裸露的导体之间易形成各种空气间隙,其工频放电特性对开关柜的绝缘性能有很大的影响。为得到开关柜内不同空气间隙类型在高海拔下的工频放电特性及其影响因素,以40.5 kV开关柜母线室存在的4种典型的空气间隙及棒-板间隙为研究对象,在人工气候实验室进行了海拔232~3000 m下的低气压工频放电特性试验。结果表明:开关柜内不同空气间隙类型的放电电压U明显不同,放电电压U随气压P下降的趋势也不同;在开关柜空气间隙海拔校正时,湿度h对间隙放电电压的影响较小,仅简单考虑气压是可行的;开关柜空气间隙的电场分布比棒-板间隙更不均匀,其放电电压U可能比棒-板间隙更低;此外,开关柜空气间隙在间隙距离d小于400 mm时放电电压U与距离d呈非线性关系。
Bare conductors in switchgear can form complicated air gaps.And AC flashover performance of these air gaps can greatly affect switchgear insulation performance.Thus,it is necessary to study the AC flashover performance of air gaps in switchgear,especially in high altitude area,and its influencing factors.In this paper,AC discharge experiment of 4 typical air gaps in bus chamber of a 40.5 kV switchgear were conducted with rod-plane air gap as reference.Then the samples were put into climate chamber and high altitude environment were simulated.Test results showed that the AC flashover performances of 4 typical air gaps are different from each other,and decreasing trends of discharge voltage U with decrement of air pressure P are also different.Influence of humidity h on U is small so that it is acceptable to perform altitude correction for air gap in switchgear only considering P.Electrical field distribution of the air gaps in switchgear is more uneven than that for rod-plane air gap,and discharge voltage U of the air gaps might be lower than that for rod-plane gap.Besides,relationship between air gap distance d and U are nonlinear when d is less than 400 mm.
出处
《电网技术》
EI
CSCD
北大核心
2017年第12期4086-4092,共7页
Power System Technology
基金
"电力设备电气绝缘国家重点实验室开放课题(EIPE16207)"项目资助
关键词
开关柜
空气间隙
工频放电特性
低气压
电场强度
间隙距离
switchgear
air gap
AC flashover performance
low air pressure
electrical field
air gap distance
