摘要
在海拔2 100m的国家特高压工程实验室,采用恒压升降法全面深入地研究了一大一小和一大两小伞形、6.25m(5支串联组成)绝缘高度的两种大尺寸复合支柱绝缘子的直流污闪特性。试验表明:一大两小伞形大尺寸复合支柱绝缘子的直流污闪特性优于一大一小伞形;大尺寸试品的直流污闪电压与盐密、灰密均成幂函数关系,盐密对U50%的影响程度明显大于灰密;与短串试品相比,盐密对大尺寸试品的影响较大;随着上、下表面污秽比的增大,大尺寸试品直流污闪电压增加不超过10%;在绝缘高度6.25m范围内,直流污闪电压与复合支柱绝缘子串长呈良好线性关系,但由于试验数据存在一定的分散性,大尺寸试品线性推导值和试验值相差约15%;大尺寸试品的紫外放电光子数大于短串,同时,受污秽不均匀分布的影响,大尺寸试品的中、下部紫外光子数稍大于上部;大尺寸试品的中、下端电弧桥接现象剧烈,电弧大范围跨接更为明显。
In order to investigate the DC pollution flashover performance of large-size composite post insulator at high altitude, this paper presents two types of large-size composite post insulators. The insulation height of each type is 6.25 m. The artificial pollution tests were carried out at high altitude areas（2 100m） in National Engineering Laboratory for Ultra High Voltage Engineering Technology（Kunming）. The pollution flashover voltage U50% was determined by the up-and-down method. The DC pollution flashover performance of large-size composite post insulator with alternating large and two small sheds design is better than that with alternating large and small sheds design. The U50% is related to both non soluble deposit density（ESDD） and equivalent salt deposit density（NSDD） by power function, where ESDD has much more significant effects on U50% than NSDD. Compared with the short-size specimen, ESDD impacts largely on the large-size specimen. The more uneven distribution of pollution, the higher U50% is, but no more than 10%. Within the insulation height range of 6.25 m, the relationship between the length of composite post insulator and the U50% is linear, but the error exists due to the dispersion of test data if U50% of the large-size specimen is directly calculated from the short-size specimen. In this paper, the error was about 15%. The ultraviolet photon number of the large-size specimen is obviously more than that of the short-size specimen. Besides, the distribution of pollution obviously affects the ultraviolet photons number. Since the contaminant on the top side surface of the large-size specimen falls on the middle and lower parts after saturated moisture, the uneven degree of pollution distribute increases, and the ultraviolet photon numbers on the middle and lower parts of the large-size specimen are greater than that on the top part. The partial discharge phenomenon on the middle and lower parts of the large-size specimen are very intense, and the arc propagates widely, even bridges couple of sheds.
出处
《电工技术学报》
EI
CSCD
北大核心
2016年第10期93-101,共9页
Transactions of China Electrotechnical Society
基金
国家自然科学基金面上项目资助(51177052)
关键词
大尺寸
复合支柱绝缘子
直流污闪特性
污秽因素
局部放电
沿面电弧
Large-size
composite post insulator
DC pollution flashover performance
pollution factors
partial discharge
arcs on the surfaces
