Effects of electrode shape on the gap breakdown characteristics in propane injection flames
YANG Haoyuan1, SHUI Kai2, WANG Zhenhua1,3, CHEN Siyi1, YOU Fei1,3, ZHANG Yun4
1. College of Safety Science and Engineering, Nanjing Technology University, Nanjing 211816, China; 2. Anhui Conch Cement Co., Ltd., Wuhu 241000, China; 3. Institute of Fire Science and Engineering, Nanjing Technology University, Nanjing 211816, China; 4. China Southern Power Grid Extra High Voltage Power Transmission Company Wuzhou Branch, Wuzhou 543002, China
Abstract：High-voltage transmission wires, a key part of electrical transmission systems, can cause serious fires. There have been few studies of the effect of electrode shapes on gap breakdown around the transmission wires. This study analyzed the effect of electrode shapes on gap breakdown with ignition conditions in terms of the breakdown voltage, breakdown polarity and breakdown arc characteristics. The tests used a high voltage power frequency discharge system (type 30 kV·A/50 kV), propane injection as a simulated fire source and combinations of rod or plate electrodes. For gaps less than 8.0 cm with flames present, the breakdown waveform had a discharge induction stage, a gap breakdown point, an arc conduction stage and a breakdown vanishing point. The average breakdown voltages and the average breakdown field strengths of the various electrode combinations were measured by setting various gap sizes. The rod-rod electrode had the slowest increase of the breakdown voltage with increasing gap size while the rod (negative)-plate (positive) electrode had the fastest increase. The air gap breakdown had polarity characteristics due to the flame flow field and buoyancy. The different electrode shapes affected the probability of forming conductive channels with positive and negative periods. When the breakdown was during a positive period, the combination of negative rod and positive plate electrodes had the highest breakdown probability, while when the breakdown was during a negative period, the combination of positive rod and negative plate electrodes had the highest breakdown probability. The results show that the evolution of the breakdown arc can be divided into the conduction stage, the combustion stage and the extinction stage. A flame significantly increases the arc volume and the upward drift. The flame flow field and the buoyancy both change the electrode discharge position. This research is important for forest fire prevention and safe operation of high voltage power grids in mountainous regions.
杨皓元, 水凯, 王振华, 陈思怡, 尤飞, 张云. 丙烷喷射火焰中电极形状对间隙击穿特性的影响[J]. 清华大学学报（自然科学版）, 2022, 62(6): 1094-1101.
YANG Haoyuan, SHUI Kai, WANG Zhenhua, CHEN Siyi, YOU Fei, ZHANG Yun. Effects of electrode shape on the gap breakdown characteristics in propane injection flames. Journal of Tsinghua University(Science and Technology), 2022, 62(6): 1094-1101.
[1] 杨赫, 徐溢卓, 李宛阳. 输电线路因山火跳闸事故统计特性与识别分析[J]. 环球市场, 2018(4):380. YANG H, XU Y Z, LI W Y. Statistical characteristics and identification analysis of power transmission line trip accident due to mountain fire[J]. Global Market, 2018(4):380. (in Chinese) [2] 秦富仓, 王玉霞. 林火原理[M]. 北京:机械工业出版社, 2014. QIN F C, WANG Y X. Forest fire principle[M]. Beijing:China Machine Press, 2014. (in Chinese) [3] 何知纯, 王沐雪. 输电线路山火跳闸机理分析及预防措施[J]. 科技资讯, 2019, 17(13):30-31. HE Z C, WANG M X. Power transmission lines fire trip mechanism analysis and preventive measures[J]. Science & Technology Information, 2019, 17(13):30-31. (in Chinese) [4] 中华人民共和国住房和城乡建设部. 110 kV~750 kV架空输电线路设计规范:GB 50545-2010[S]. 北京:中国计划出版社, 2010. Ministry of Housing and Urban-Rural Development of the People's Republic of China. Code for design of 110kV-750kV overhead transmission line:GB 50545-2010[S]. Beijing:China Planning Press, 2010. (in Chinese) [5] 文刚, 金晶, 周纺荣, 等. 110kV及以上电压等级输电线路因山火跳闸分析及防治[J]. 电工技术, 2020(19):51-54. WEN G, JIN J, ZHOU F R, et al. Analysis and prevention of wildfire tripping of 110kV and above transmission line[J]. Electric Engineering, 2020(19):51-54. (in Chinese) [6] 清华大学深圳研究生院. 山火对高压输电线路安全运行的危害[EB/OL]. (2021-11-17)[2021-11-29]. http://inmrchina.com/. Shenzhen Graduate School of Tsinghua University. The harm of mountain fire to the safe operation of high voltage transmission line[EB/OL]. (2021-11-17)[2021-11-29]. http://inmrchina.com/. (in Chinese) [7] 国家统计局. 2021中国统计年鉴[M]. 北京:中国统计出版社, 2021. National Bureau of Statistics. 2021 China statistical yearbook[M]. Beijing:China Statistics Press, 2021. (in Chinese) [8] 王振华, 尤飞, 张云, 等. 易诱发输电线路跳闸的山火时空分布规律及发生频率分析[J]. 安全与环境学报, 2016, 16(3):86-93. WANG Z H, YOU F, ZHANG Y, et al. Temporal-spatial distribution regularity and the liability of the wildfire incidence frequency in inducing the power transmission line electrical trips[J]. Journal of Safety and Environment, 2016, 16(3):86-93. (in Chinese) [9] 杨康, 陈海翔, 桑荣剑, 等. 输电线路山火跳闸机理的模拟实验研究[J]. 火灾科学, 2016, 25(2):73-78. YANG K, CHEN H X, SANG R J, et al. Simulative experimental study on wildfire induced breakdown of transmission lines[J]. Fire Safety Science, 2016, 25(2):73-78. (in Chinese) [10] 黄勇, 周恩泽, 魏瑞增, 等. 典型植被火条件下1.2~2.7m导线-板空气间隙击穿特性[J]. 广东电力, 2021, 34(9):105-110. HUANG Y, ZHOU E Z, WEI R Z, et al. Breakdown characteristics of 1.2-2.7m conductor-plane air gap under typical vegetation flame condition[J]. Guangdong Electric Power, 2021, 34(9):105-110. (in Chinese) [11] SADURSKI K J, REYNDERS J P. High voltage AC breakdown in presence of fires[C]//Proceedings of the 6th International Symposium on High Voltage Engineering. New Orleans, USA, 1989:1-4. [12] WEST H J, MCMULLAN D W. Fire induced flashover of EHV transmission lines[J]. IEEE Transactions on Power Apparatus and Systems, 1979, 98(4):1142. [13] ALBINI F A. Spot fire distance from burning trees:A predictive model[R]. Ogden, USA:Intermountain Forest and Range Experiment Station, 1979. [14] MITCHELL J W. Power line failures and catastrophic wildfires under extreme weather conditions[J]. Engineering Failure Analysis, 2013, 35:726-735. [15] WINANDS G J J, LIU Z, PEMEN A J M, et al. Analysis of streamer properties in air as function of pulse and reactor parameters by ICCD photography[J]. Journal of Physics D:Applied Physics, 2008, 41(23):234001. [16] BRIELS T M P, VAN VELDHUIZEN E M, EBERT U. Time resolved measurements of streamer inception in air[J]. IEEE Transactions on Plasma Science, 2008, 36(4):908-909.
2022, Vol. 62 
