Abstract：In recent years, the room temperature vulcanized (RTV) silicone rubber coatings, widely used in outdoor high-voltage insulators on overhead transmission lines, could improve the contamination performance of insulators. The RTV coatings usually lose its hydrophobicity and result in further degradation under long-term partial discharge. Therefore, it is necessary to study the characteristic of partial discharge along the RTV coated insulation surfaces. The process of partial discharge includes corona discharge, streamer discharge and arc discharge. The streamer propagation along the insulation surface is a complexest physical process. This paper focuses on the characteristics of streamer propagation along the RTV coating. In three-electrode arrangement, the characteristics of streamer propagation along clean and the RTV coated insulation surfaces are measured through three photomultipliers. The electric field required for streamer stable propagation along the RTV coated insulation surfaces is larger,and the velocity is slower in the same electric field. Furthermore, the characteristics of streamer propagation along insulation surfaces with different RTV coating are different. Some RTV coating inhibits the streamer greatly, hence, the characteristics of partial discharge along the different RTV coated insulation surfaces are different in the operation condition.
[1] IEEE Standard 1523. IEEE Guide for the application, maintenance, and evaluation of room temperature vulcanizing(RTV) silicone rubber coatings for outdoor ceramic insulators[S]. 2002. [2] Carberry R E, Schneider H M. Evaluation of RTV coating for station insulators subjected to coastal contamination[J]. IEEE Transactions on Power Delivery, 1989, 4(1): 577-585. [3] Gorur R S, Orbeck T. Surface dielectric behavior of polymeric insulation under HV outdoor conditions[J]. IEEE Transactions on Electrical Insulation, 1991, 26(5): 1064-1072. [4] Cherney E A, Hackam R, Kim S H. Porcelain insulator maintenance with RTV silicone rubber coatings[J]. IEEE Transactions on Power Delivery, 1991, 6(3): 1177-1181. [5] Deng Hui, Hackam R. Low-molecular weight silicone fluid in RTV silicone rubber coatings[J]. IEEE Transactions on Dielectrics and Electrical Insulation, 1999, 6(1): 84-94. [6] Cherney E A, Gorur R S. RTV silicone rubber coatings for outdoor insulators[J]. IEEE Transactions on Dielectrics and Electrical Insulation, 1999, 6(5): 605-611. [7] Homma H, Mirley C L, Ronzello J, et al. Field and laboratory aging of RTV silicone insulator coatings[J]. IEEE Transactions on Power Delivery, 2000, 15(4): 1298-1303. [8] 高海峰, 贾志东, 关志成. 运行多年RTV涂料绝缘子表面涂层老化分析研究[J]. 中国电机工程学报, 2005, 25(9): 158-163. Gao Haifeng, Jia Zhidong, Guan Zhicheng. Aging study on RTV coating covered on insulators and energized for many years[J]. Proceedings of the CSEE, 2005, 25(9): 158-163. [9] Gao Haifeng, Jia Zhidong, Guan Zhicheng, et al. Investigation on field-aged RTV-coated insulators used in heavily contaminated areas[J]. IEEE Transac- tions on Power Delivery, 2007, 22(2): 1117-1124. [10] Mahajan S M, Sudashan T S, Dougal R A. Avalanches near a dielectric spacer in nitrogen gas[C]. ‘Gaseous dielectrics V’, Pergamon, 1987. [11] Gallimberti I, Marchesi G, Niemeyer L. Streamer corona at an insulator surface[C]. Seventh International Symposium on High Voltage Engineering Dresden, Germany, 1991. [12] Allen N L, Mikropoulos P N. Streamer propagation along insulating surfaces[J]. IEEE Transactions on Dielectrics and Electrical Insulation, 1999, 6(3): 357-362. [13] Akyuz M, Gao L, Cooray V, et al. Positive streamer discharges along insulating surfaces[J]. IEEE Transac- tions on Dielectrics and Electrical Insulation, 2001, 8(6): 902-910. [14] Allen N L, Hashem A, Rodrigo H, et al. Streamer development on silicone-rubber insulator surfaces[J]. IEE Proceedings-Science Measurement and Technology, 2004, 151(1): 31-38. [15] Mikropoulos P N. Streamer propagation along room- temperature-vulcanised silicon-rubber-coated cylindrical insulators[J]. IET Science Measurement & Technology, 2008, 2(4): 187-195. [16] 孟晓波, 惠建峰, 卞星明, 等. 低气压下流注放电特性的研究[J]. 中国电机工程学报, 2011, 31(25): 139-149. Meng Xiaobo, Hui Jianfeng, Bian Xingming, et al. Research on the characteristic of streamer discharge at low air pressure[J]. Proceedings of the CSEE, 2011, 31(25): 139-149. [17] Yamano Y, Kasuga K, Kobayashi S, et al. Surface flashover and charging characteristics on various kinds of alumina under nonuniform electric field in vacuum [C]. 20th International Symposium on Discharges and Electrical Insulation in Vacuum, 2002: 115-118. [18] 汪沨, 邱毓昌, 张乔根, 等. 冲击电压作用下影响表面电荷积聚过程的因素分析[J]. 电工技术学报, 2001, 16(05): 51-54. Wang Feng, Qiu Yuchang, Zhang Qiaogen, et al. Analysis of factors influence charge accumulation on insulator surface under impulse voltage[J]. Transactions of China Electrotechnical Society, 2001, 16(05): 51-54. [19] 杨莉, 汤俊萍, 邱爱慈, 等. 纳秒脉冲下真空中绝缘子表面带电特性[J]. 强激光与粒子束, 2008, 20(12): 2091-2095. Yang Li, Tang Junping, Qiu Aici, et al. Urface charge characteristics on insulators in vacuum under nanosecond pulse excitation[J]. High Power Laser and Part Icle Beams, 2008, 20(12): 2091-2095. [20] 吕金壮. 氧化铝陶瓷的陷阱分布对其真空中沿面闪络特性的影响[D]. 北京: 华北电力大学, 2003.
2014, Vol. 29 
