Numerical Simulation Study on Negative Corona Discharge of Small Ellipsoidal Electrode
Lu Binxian1, Yue Zhanbing1, Wang Yijing2, Huang Weixiao1, Ma Hao1
1. School of Electrical and Electronic Engineering North China Electric Power University Beijing 100054 China; 2. Heilongjiang Provincial Government Investment Project Contruction Management Center Harbin 150001 China
Abstract:Corona discharge is a common partial discharge that may occur in important power transmission equipment such as transformers, circuit breakers and gas insulated switchgear (GIS), causing serious damage to the insulation of the equipment. In recent years, researchers have studied the mechanism of negative corona discharge of electrodes with different tip shapes by numerical simulation. But there is no research on the negative corona discharge of small ellipsoidal electrodes. In this paper, the negative corona discharge model of ellipsoid electrode is established by coupling the fluid dynamics equation and Poisson equation. The discharge current pulses and the distribution of positive ion concentration are analyzed by using the finite element method. The ellipsoid electrode is equivalent to a symmetric simulation model. The model is placed in a simulated air domain with a side length of 10 mm, and the bottom of the simulation domain is a ground plane electrode with a radius of 10 mm. The ellipsoid electrode is located 3.3 mm above the ground plane electrode. After setting the initial density distribution of electrons and positive ions, and determining the discharge voltage and simulation time, the current pulses during the negative corona discharge can be obtained. In this way, an axisymmetric ellipsoid electrode negative corona discharge model is formed, which greatly reduces the simulation time. The lengths of the ellipsoid electrode half-axis a and b are set as 0.35 mm and 0.25 mm, respectively. By applying DC voltage, the ellipsoid electrode potential is -4.2 kV, and the simulation time is set as 20 000 ns. The results show that only the first current pulse is the point discharge pulse appearing at 0° position (point A) of the ellipsoid electrode, and the other current pulses are the ring discharge pulse appearing near 90° position (point C) of the ellipsoid electrode. The amplitudes of all ring discharge pulse currents are greater than that of point discharge pulse currents. The shape of the ellipsoid electrode is kept unchanged, and the applied voltage is set to 3.6, 3.7, 3.9, 4.1 and 4.2 kV, respectively. The simulation time is 20 000 ns. The results show that the amplitude of the first current pulse of the ellipsoid electrode increases with the increase of voltage. The higher the applied voltage, the more current pulses during the negative corona discharge of the ellipsoid electrode. But the effect of the applied voltage on the negative corona discharge mode is small. The shape of the ellipsoid electrode is changed by keeping the applied voltage constant. Given that a is always greater than b, the results show that the smaller the ratio of half-axis a to b of the ellipsoid electrode, the more current pulses during negative corona discharge of the ellipsoid electrode. The greater the ratio of half-axis a and b of the ellipsoid electrode, the greater the proportion of the number of ring discharge pulses to the total number of discharge pulses. Therefore, changing the shape of the ellipsoid electrode not only changes the number, amplitude and occurrence time of current pulses during negative corona discharge, but also changes the discharge mode. The following conclusions can be drawn from the simulation analysis: (1) The ring mode discharge mainly occurs at the position where the electric field intensity is maximum before the pulse current. The greater the ratio of half-axis a to b of the ellipsoid electrode, the greater the electric field intensity at point C, and the greater the proportion of the number of ring mode discharge pulses to the total number of current pulses. (2) The greater the applied voltage to the same ellipsoid electrode, the earlier the first current pulse appearing and the greater the amplitude. (3) The number, amplitude, occurrence time and discharge mode of current pulses during discharge of ellipsoid electrodes with different shapes are different.
卢斌先, 岳战兵, 王宜静, 黄未啸, 马浩. 椭球电极负电晕放电的数值仿真研究[J]. 电工技术学报, 2023, 38(13): 3379-3387.
Lu Binxian, Yue Zhanbing, Wang Yijing, Huang Weixiao, Ma Hao. Numerical Simulation Study on Negative Corona Discharge of Small Ellipsoidal Electrode. Transactions of China Electrotechnical Society, 2023, 38(13): 3379-3387.
[1] 陈迪, 苏春强, 安海舰, 等. 淋雨条件下220 kV绝缘子均压环电晕放电特性研究[J]. 高压电器, 2021, 57(12): 170-176. Chen Di, Su Chunqiang, An Haijian, et al.Research on corona discharge characteristics of grading ring of 220 kV insulator under rainfall condition[J]. High Voltage Apparatus, 2021, 57(12): 170-176. [2] 程金金, 李学宝, 张静岚, 等. 交直流并行架设下的负极性电晕电流脉冲特性[J]. 高电压技术, 2020, 46(9): 3343-3351. Cheng Jinjin, Li Xuebao, Zhang Jinglan, et al.Characteristics of negative corona current pulses from DC conductor parallel with AC conductor[J]. High Voltage Engineering, 2020, 46(9): 3343-3351. [3] 黄明祥, 郭志彬, 潘立志, 等. 交流单点电晕放电可听噪声纯音分量空间传播特性研究[J]. 华北电力大学学报(自然科学版), 2022, 49(2): 63-71. Huang Mingxiang, Guo Zhibin, Pan Lizhi, et al.Propagation characteristics of pure tones of audible noise generated by single AC corona discharge source[J]. Journal of North China Electric Power University (Natural Science Edition), 2022, 49(2): 63-71. [4] 李维虎, 张锦, 万保权, 等. 正极性电晕放电脉冲特性仿真研究[J]. 高压电器, 2018, 54(12): 129-136. Li Weihu, Zhang Jin, Wan Baoquan, et al.Simulation study on pulse of positive corona discharge[J]. High Voltage Apparatus, 2018, 54(12): 129-136. [5] 张晓琴, 朱洪斌, 余翔, 等. 大气相对湿度对聚酰亚胺薄膜表面电晕特性及老化过程的影响[J]. 绝缘材料, 2021, 54(11): 134-139. Zhang Xiaoqin, Zhu Hongbin, Yu Xiang, et al.Effects of ambient relative humidity on surface corona properties and ageing process of polyimide films[J]. Insulating Materials, 2021, 54(11): 134-139. [6] 梁英, 高丽娟, 董平平. 机械应力对复合套管用硅橡胶材料电晕老化特性的影响[J]. 华北电力大学学报(自然科学版), 2017, 44(4): 50-56. Liang Ying, Gao Lijuan, Dong Pingping.Influence of mechanical stress on the corona and aging characteristics of composite casings made by silicone rubber materials[J]. Journal of North China Electric Power University (Natural Science Edition), 2017, 44(4): 50-56. [7] 李炼炼, 孟刚, 邓慰, 等. 输变电设备电晕放电紫外图谱量化参数提取[J]. 高压电器, 2017, 53(12): 229-235. Li Lianlian, Meng Gang, Deng Wei, et al.Quantification parameters extraction from ultraviolet image of corona discharge of power transmission and transformation equipment[J]. High Voltage Apparatus, 2017, 53(12): 229-235. [8] 牛海清, 徐乐平, 李小潇, 等. SF6气体正极性电晕放电特性仿真研究[J]. 高电压技术, 2021, 47(11): 4063-4071. Niu Haiqing, Xu Leping, Li Xiaoxiao, et al.Simulation and study of positive corona characteristics in SF6 gas[J]. High Voltage Engineering, 2021, 47(11): 4063-4071. [9] 艾嘉伟, 徐乐平, 牛海清, 等. 空气正极性电晕放电微观仿真及模型系数对脉冲电流特性的影响[J]. 高电压技术, 2021, 47(12): 4377-4387. Ai Jiawei, Xu Leping, Niu Haiqing, et al.Micro-simulation of air positive corona and the influence of model coefficient on pulse current characteristics[J]. High Voltage Engineering, 2021, 47(12): 4377-4387. [10] 何寿杰, 张钊, 李庆, 等. 针板负直流电晕放电中的脉冲等离子体特性[J]. 高电压技术, 2018, 44(3): 870-875. He Shoujie, Zhang Zhao, Li Qing, et al.Characteristics of pulsing plasma in needle-plane corona discharge driven by negative direct power source[J]. High Voltage Engineering, 2018, 44(3): 870-875. [11] Trichel G W.The mechanism of the negative point to plane corona near onset[J]. Physical Review, 1938, 54(12): 1078-1084. [12] Antao D S, Staack D A, Fridman A, et al.Atmospheric pressure dc corona discharges: operating regimes and potential applications[J]. Plasma Sources Science and Technology, 2009, 18(3): 035016. [13] 徐建源, 陈会利, 林莘, 等. 针-板电极下SF6的电晕放电特性分析[J]. 高电压技术, 2019, 45(1): 293-300. Xu Jianyuan, Chen Huili, Lin Xin, et al.Analysis of corona discharge characteristics of SF6 under pin-plate electrodes[J]. High Voltage Engineering, 2019, 45(1): 293-300. [14] Chen She, Li Kelin, Nijdam S.Transition mechanism of negative DC corona modes in atmospheric air: from Trichel pulses to pulseless glow[J]. Plasma Sources Science and Technology, 2019, 28(5): 055017. [15] Morrow R.Theory of stepped pulses in negative corona discharges[J]. Physical Review A, General Physics, 1985, 32(6): 3821-3824. [16] Tarasenko V F, Kuznetsov V S, Panarin V A, et al.Role of streamers in the formation of a corona discharge in a highly nonuniform electric field[J]. JETP Letters, 2019, 110(1): 85-89. [17] Lu Binxian, Ma Hao, Xiong Jun.Study on negative corona discharge of the small spherical metal electrode[J]. IEEE Transactions on Plasma Science, 2021, 49(7): 2055-2062. [18] Lu Binxian, Liao Sizhuo, Zhu Jingjing, et al.Comparison of dust particle dynamics under different electrode shapes at the early stage of negative corona discharge[J]. IEEE Transactions on Plasma Science, 2019, 47(11): 4915-4922. [19] Lu B X, Zhu J J.Comparison of discharge mechanism of negative corona between hyperboloid and hemispherical electrodes[J]. AIP Advances, 2018, 8(12): 125206. [20] Morrow R, Sato N.The discharge current induced by the motion of charged particles in time-dependent electric fields; Sato’s equation extended[J]. Journal of Physics D: Applied Physics, 1999, 32(5): L20-L22. [21] Lu B X, Sun H Y.The role of photoionization in negative corona discharge[J]. AIP Advances, 2016, 6(9): 095111. [22] Deng F C, Ye L Y, Song K C.Numerical studies of Trichel pulses in airflows[J]. Journal of Physics D: Applied Physics, 2013, 46(42): 425202. [23] Georghiou G E, Papadakis A P, Morrow R, et al.Numerical modelling of atmospheric pressure gas discharges leading to plasma production[J]. Journal of Physics D: Applied Physics, 2005, 38(20): R303-R328. [24] Kang W S, Park J M, Kim Y, et al.Numerical study on influences of barrier arrangements on dielectric barrier discharge characteristics[J]. IEEE Transactions on Plasma Science, 2003, 31(4): 504-510. [25] Liang Xinghua, Jayaram S, Berezin A A, et al.Modeling of the electrical parameters of a wire-cylinder electrostatic precipitator under pulse energization[J]. IEEE Transactions on Industry Applications, 2002, 38(1): 35-42. [26] Greenwood A.Negative point-to-plane corona—a new mode of the discharge[J]. Nature, 1951, 168(4262): 41-42. [27] Greenwood A.The mechanism of the ring discharge in negative point-to-plane corona[J]. Journal of Applied Physics, 1952, 23(12): 1316-1319.