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Plasma Characteristics of Positive Leader Inception and Development |
Peng Changzhi1, Dong Xuzhu1, Zhao Yanpu1, Li Zhijun2, Zheng Yu1 |
1. School of Electrical Engineering and Automation Wuhan University Wuhan 430072 China; 2. State Key Laboratory of Environmental Protection for Power Grid China Electric Power Research Institute Wuhan 430074 China |
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Abstract Long air gap discharge is similar to lightning discharge, which is known as atmospheric plasma. One of the primary processes of long air gap discharge is leader discharge. Despite extensive experimental and simulation work related to leader discharge has been carried out, the conditions for leader initiation remain unclear. In this study, we use experimental data and numerical model to investigate the favorable conditions for leader inception. First, a 10m air gap discharge observation system was built. The observation system includes a high-speed camera, a current measuring device, and a voltage measuring sensor. The high voltage electrode was applied four different rise rate voltages. Using the measured current data, the inception time of the leader discharge can be easily classified. The injected charge for leader inception could be obtained by integrating the current with time. Hence, we obtained the minimum amount of injected charge required for leader initiation at various voltage rise rates. Secondly, the measured current of the 10m discharge gap can be used to simulate plasma discharge process. The key physical quantities that influence channel temperature are the magnitude and duration of the current in the discharge channel. By using the experimental current as the input of plasma model, the gas temperature in the discharge channel could be calculated. Finally, the micro process and luminous properties of the discharge channel during leader development are then examined. The leader discharge current generally fluctuates within a certain range during the leader development process. The plasma model was used to compute the plasma density and conductivity in the discharge channel. Based on the simplified plasma discharge model, the leader formation process of 10m rod plate gap are simulated under different impulse voltage. The evolution laws of the leader channel's streamer stem temperature, conductivity, and thermodynamic parameters are investigated. The main conclusions are as follows: ① For the 10m rod plate gap, the first streamer discharge injected more charge, and the stem can be easily heated to exceed 2 000K before leader inception. At the same peak voltage, with the increase of applied voltage wave front time, the initial trigger temperature of the leader decreases. ② The initial charge injected by the leader is occasionally less than 1μC. The injected charge of the leader can be as low as 0.66μC. ③ During the development of the leader, the channel temperature is relatively stable, maintained at about 4 000K. The generation of electrons is mainly from thermal ionization, and the conductivity of the streamer stem fluctuates within the range of 1~10S/m.
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Received: 30 September 2021
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[1] 蔡国伟, 雷宇航, 葛维春, 等. 高寒地区风电机组雷电防护研究综述[J]. 电工技术学报, 2019, 34(22): 4804-4815. Cai Guowei, Lei Yuhang, Ge Weichun, et al.Review of research on lightning protection for wind turbines in alpine areas[J]. Transactions of China Electro-technical Society, 2019, 34(22): 4804-4815. [2] Gallimberti I, Bacchiega G, Bondiou-Clergerie A, et al.Fundamental processes in long air gap dis-charges[J]. Comptes Rendus Physique, 2002, 3(10): 1335-1359. [3] 刘晓鹏, 赵贤根, 刘磊, 等. 长空气间隙放电通道的绝缘恢复特性[J]. 电工技术学报, 2021, 36(2): 380-387. Liu Xiaopeng, Zhao Xiangen, Liu Lei, et al.Characteristics of the discharge channel during the relaxation process in the long air gap[J]. Transa-ctions of China Electrotechnical Society, 2021, 36(2): 380-387. [4] 谢耀恒, 彭平, 刘赟, 等. 低电压上升率条件下正极性不连续先导发展特性[J]. 电工技术学报, 2018, 33(14): 3406-3413. Xie Yaoheng, Peng Ping, Liu Yun, et al.The development characteristics of the discontinuous leader under the positive switching impulse with low rate of voltage rising[J]. Transactions of China Electrotechnical Society, 2018, 33(14): 3406-3413. [5] 刘晓鹏, 董曼玲, 邓虎威, 等. 空气间隙击穿后放电通道内的气体运动特性[J]. 电工技术学报, 2021, 36(13): 2667-2674. Liu Xiaopeng, Dong Manling, Deng Huwei, et al.Movement characteristics of the gas in discharge channel after air gap breakdown[J]. Transactions of China Electrotechnical Society, 2021, 36(13): 2667-2674. [6] 郭子炘, 李庆民, 于万水, 等. 负极性雷击下地面物体上行先导稳定起始的初始流注动态临界长度判据[J]. 中国电机工程学报, 2020, 40(5): 1713-1722. Guo Zixin, Li Qingmin, Yu Wanshui, et al.The dynamic critical length criterion of initial streamer for the stable upward leader inception under negative lightning strikes[J]. Proceedings of the CSEE, 2020, 40(5): 1713-1722. [7] 蔡力, 柯逸丰, 李进, 等. 基于高速摄像观测的风电场雷击风机发展过程和特性分析[J]. 电工技术学报, 2021, 36(增刊1): 303-310. Cai Li, Ke Yifeng, Li Jin, et al.Development process and characteristic analysis of the natural lightning strike on wind turbine based on high-speed camera observation[J]. Transactions of China Electrotech-nical Society, 2021, 36(S1): 303-310. [8] Becker K H, Kogelschatz U, Schoenbach K H, et al.Non-equilibrium air plasmas at atmospheric pre-ssure[M]. Los Angeles: CRC Press, 2004. [9] 臧奕茗, 钱勇, 刘伟, 等. C4F7N/CO2混合气体中尖端缺陷的流注放电仿真研究[J]. 电工技术学报, 2020, 35(1): 34-42. Zang Yiming, Qian Yong, Liu Wei, et al.Simulation study on streamer of tip defects in C4F7N/CO2 mixed gas[J]. Transactions of China Electrotechnical Society, 2020, 35(1): 34-42. [10] Hare B M, Scholten O, Dwyer J, et al.Needle-like structures discovered on positively charged lightning branches[J]. Nature, 2019, 568(7752): 360-363. [11] Zhuang Chijie, Zeng Rong.A positivity-preserving scheme for the simulation of streamer discharges in non-attaching and attaching gases[J]. Communi-cations in Computational Physics, 2014, 15(1): 153-178. [12] Chen She, Heijmans L C J, Zeng Rong, et al. Nano-second repetitively pulsed discharges in N2-O2 mixtures: inception cloud and streamer emergence[J]. Journal of Physics D: Applied Physics, 2015, 48(17): 175201. [13] Zhao Xiangen, Liu L, Wang Xiaolei, et al.On the velocity-current relation of positive leader discharges[J]. Geophysical Research Letters, 2019, 46(1): 512-518. [14] Les R G.Positive discharges in long air gaps at Les Renardieres-1975 results and conclusions[J]. Electra, 1977, 53: 31-153. [15] Zhao Xiangen, Becerra M, Yang Yongchao, et al.Elongation and branching of stem channels produced by positive streamers in long air gaps[J]. Scientific Reports, 2021, 11(1): 4120. [16] da Silva C L, Pasko V P. Dynamics of streamer-to-leader transition at reduced air densities and its implications for propagation of lightning leaders and gigantic jets[J]. Journal of Geophysical Research: Atmospheres, 2013, 118(24): 13561-13590. [17] Gallimberti I.The mechanism of the long spark formation[J]. Le Journal De Physique Colloques, 1979, 40(C7): 193. [18] Liu Lipeng, Becerra M.Gas heating dynamics during leader inception in long air gaps at atmospheric pressure[J]. Journal of Physics D: Applied Physics, 2017, 50(34): 345202. [19] Liu Lipeng, Becerra M.On the critical charge required for positive leader inception in long air gaps[J]. Journal of Physics D: Applied Physics, 2018, 51(3): 035202. [20] Wu Chuanqi, Xie Shijun, Qi Fei, et al.Effect of corona discharges on the inception of positive upward leader-streamer system[J]. International Journal of Modern Physics B, 2013, 27(28): 1350165. [21] Carrara G, Thione L.Switching surge strength of large air gaps: a physical approach[J]. IEEE Transactions on Power Apparatus and Systems, 1976, 95(2): 512-524. [22] Young F S, Schneider H M, Gutman Y M, et al. USA-USSR investigation of1200-kV tower insu-lation[J]. IEEE Transactions on Power Apparatus and Systems, 1980, PAS-99(2): 462-470. [23] Cui Yingzhe, Zhuang Chijie, Zhou Xuan, et al.The dynamic expansion of leader discharge channels under positive voltage impulse with different rise times in long air gap: experimental observation and simulation results[J]. Journal of Applied Physics, 2019, 125(11): 113302. [24] 苟学强, 张义军, 李亚珺, 等. 闪电双向先导理论及观测: 极性不对称、不稳定及间歇性[J]. 物理学报, 2018, 67(20): 400-410. Gou Xueqiang, Zhang Yijun, Li Yajun, et al.Theroy and observation of bidirectional leader of lightning: Polarity asymmetry, instability, and intermittency[J]. Acta Physica Sinica, 2018, 67(20): 400-410. [25] 杨亚奇, 李卫国, 夏喻, 等. 低气压下长间隙交直流放电特性研究[J]. 电工技术学报, 2018, 33(5): 1143-1150. Yang Yaqi, Li Weiguo, Xia Yu, et al.Research of AC and DC discharge characteristics of long gap under low pressure[J]. Transactions of China Electro-technical Society, 2018, 33(5): 1143-1150. [26] Huang Shengxin, Chen Weijiang, Pei Zhehao, et al. The discharge preceding the intense reillumination in positive leader steps under the slow varying ambient electric field[J]. Geophysical Research Letters, 2020, 47(3): e2019GL086183. [27] Raĭzer I P.Gas discharge physics[M]. Berlin: Springer, 1997. [28] Da Silva C L, Sonnenfeld R G, Edens H E, et al. The plasma nature of lightning channels and the resulting nonlinear resistance[J]. Journal of Geophysical Research: Atmospheres, 2019, 124(16): 9442-9463. [29] Cheng Chen, Liu Lipeng, He Hengxin, et al.Experi-mental study of the dynamics of leader initiation with a long dark period[J]. Journal of Physics D: Applied Physics, 2020, 53(20): 205203. |
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