800kv长串绝缘子污闪特性及绝缘子选择研究
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第29卷 第22期 中 国 电 机 工 程 学 报 Vol.29 No.22 Aug. 5, 2009 94 2009年8月5日 Proceedings of the CSEE ©2009 Chin.Soc.for Elec.Eng.
文章编号：0258-8013 (2009) 22-0094-06 中图分类号：TM 85 文献标志码：A 学科分类号：470⋅40
±800 kV长串绝缘子污闪特性及绝缘子选择研究 宿志一1，周军1，高海峰1，伊藤进2，近藤诚一2(1．中国电力科学研究院，北京市 海淀区 100192；2．日本碍子株式会社，小牧 485-8566，日本)
Study on Pollution Performance and Insulation Selection of ±800 kV Long String Insulators SU Zhi-yi1, ZHOU Jun1, GAO Hai-feng1, Susumu ITO2, Seiichi KONDO2(1. China Electric Power Research Institute, Haidian District, Beijing 100192, China; 2. NGK Insulators Ltd., Komaki 485-8566, Japan)
ABSTRACT: The pollution flashover performance of large tonnage insulators typically used in ±800 kV DC transmission lines were studied in this paper. As V string and double I string would probably be adopted in lines, the influence that structure exerts on pollution flashover voltage has been tested. Test results showed that, for large tonnage insulators, a linear relationship between DC pollution flashover voltage and string length has been presented. The pollution flashover performance of V strings generally coincide with that of I string, and the test results of I string can be directly used to V strings. While the space between paralleled strings has significant influence on pollution flashover performance, and the influencing effect varied with string lengths. Based on the correction of relationship between salt deposit density (SDD) and non-soluble material deposit density (NSDD), methods of external insulation parameter calculation and insulator selection for ±800 kV UHV DC transmission projects were introduced.
KEY WORDS: ±800 kV; DC line; long string insulator;
pollution test
摘要：对±800 kV直流输电线路上可能用到的几种典型大吨
位绝缘子的污闪特性进行了系统的人工污秽试验研究。针对线路中可能用到的V型串及双I串并联结构，通过试验分析了它们对绝缘子串污闪电压的影响。结果表明，大吨位绝缘子的直流污闪电压与串长之间仍存在较好的线性关系，V型绝缘子串的污闪特性与I型串基本一致，可以直接使用I型串的试验结果，但并联绝缘子串间距对绝缘子串污闪特性存在显著影响，且串长不同时，并联绝缘子串间距对其污闪电压的影响效果不同。基于上述试验结果，并考虑了现场等值盐密与试验盐密的校正关系，给出了±800 kV特高压直流输电
工程外绝缘参数计算和线路绝缘子选型的方法。
关键词：±800 kV；直流线路；长串绝缘子；污秽试验
0 INTRODUCTION Lots of operation experience, both domestic and abroad showed that pollution deposited on insulators under DC condition was heavier than that under AC condition. Even if under the same pollution level, the DC pollution flashover voltage of insulator was lower than that of AC condition [1]. Among China’s power grid framework, ±800 kV DC
transmission lines are the main channel for the realization of cross region transmission and optimized allocation of power resources. Therefore, external insulation reliability of ±800 kV transmission lines
deserves more attention for it will become the deciding factor of ±800 kV transmission project
external insulation design [2-3]. In ±800 kV DC transmission lines, 300 kN and above large tonnage insulators need to be widely used. With the increase of insulator string length, the string type needs to be changed, such as the adoption of V string. In order to solve the difficulties of external insulation design and insulator selection in ±800 kV
DC transmission projects, the pollution performances of typical high strength insulators have been studied. Then, the influence of string length, V type string, and space between double paralleled strings on pollution flashover performance was analyzed. According to the test results and combined with various correction factors of pollution flashover voltage, the parameter of external insulation design for ±800 kV transmission
lines could be drawn out. 第22期 宿志一等： ±800 kV长串绝缘子污闪特性及绝缘子选择研究 95 1 POLLUTION FLASHOVER PERFOR- MANCES OF INSULATORS TO BE USED ON ±800 kV TRANSMISSION LINES
1.1 Test Method The pollution test with solid layer method was performed in accordance with IEC 61245—1993 [4]. The pollutants deposited on specimen insulators were simulated by NaCl and Kaolin powder. During test, the specimens were firstly added voltage, and then wetted with clean fog until flashover. The 50% DC pollution flashover voltage (U50%) of the string was
acquired, through Up-and-Down method. 1.2 Specimen Specimens included 300 kN fog insulators
CA–756EZ, 550 kN fog insulators CA–785EZ, 300 kN double sheds porcelain suspension insulators XZWP–300, 300 kN three sheds insulators CA– 776EZ, 420 kN three sheds insulators CA–778EZ, 300 kN glass suspension insulators FC300P, and composite insulators with four shed types. Tab.1 lists the parameters of porcelain and glass insulators, and Fig.1 shows insulator profiles. Tab.2 lists the parameters of composite insulators, and Fig.2 shows 表1 悬式绝缘子的几何参数 Tab. 1 Parameters of porcelain and glass insulators
