摘要
在电弧发展至临界弧长的临界时刻,绝缘子同时存在沿面电弧与飘弧,会对绝缘子的交流污闪电压(U50%)产生影响。本研究根据绝缘子平面展开模型,考虑空气电弧特性、飘弧长度及染污不均匀性(上、下表面盐密比,T/B)对绝缘子交流污闪电压的影响,推导修正了交流污闪模型,编程计算了交流大吨位CA-590、CA-597型普通绝缘子,XWP-420型双伞绝缘子的污闪电压;通过试验对比验证了模型的准确性与合理性;通过分析不同等值盐密(ESDD)下T/B与临界泄漏电流(Ic)的关系,揭示了T/B影响U50%的原因。结果表明:ESDD与T/B对污闪电压的影响相互独立,按经验公式拟合得出CA-590、CA-597型普通绝缘子污闪电压的不均匀修正系数(N)为0.124;U50%随飘弧长度的增加近似呈线性下降,ESDD越大,飘弧对U50%的影响越小,其变化规律与绝缘子表面积污特征影响Ic的显著性有关。
At the critical moment when the arc develops to the critical arc length, there are surface arc and floating arc on the insulator at the same time, which will affects the AC pollution flashover voltage(U50%) of insulator. According to the plane expansion model of insulator, the influences of air arc characteristic, floating arc length, and contamination inhomogeneity(the ratio of upper and lower surface salt density, T/B) on the pollution flashover voltage of insulator were considered, and the AC pollution flashover model was deduced and modified. The pollution flashover voltage of AC large tonnage CA-590 and CA-597 common insulators and XWP-420 double umbrella insulator were calculated. The accuracy and rationality of the model were verified comparatively by experiment. The relationship between T/B and the critical leakage current(Ic) under different equivalent salt density(ESDD) was analyzed to reveal the reason why T/B affects U50%. The results show that the effects of ESDD and T/B on the pollution flashover voltage are independent of each other. The non-uniform correction coefficient(N) of the pollution flashover voltages of CA-590 and CA-597 common insulator fitted by empirical formula is 0.124. The U50%decreases approximately linearly with the increase of floating arc length, and the larger the ESDD,the smaller the effect of floating arc on the U50%, and the change law is related to the significance of surface pollution characteristics of insulators affecting Ic.
作者
颜子威
黄瑞平
田亮
王毅
YAN Ziwei;HUANG Ruiping;TIAN Liang;WANG Yi(School of Electrical Engineering,Beijing Jiaotong University,Beijing 100044,China;State Grid China Electric Power Research Institute,Beijing 100192,China)
出处
《绝缘材料》
CAS
北大核心
2020年第3期68-76,共9页
Insulating Materials
基金
国家电网公司科技项目(GY71-17-033)。
关键词
绝缘子
交流污闪模型
空气飘弧
临界弧长
人工污秽试验
泄漏电流
insulator
AC pollution flashover model
air floating arc
critical arc length
artificial contamination test
leakage current
