|
|
Physical Mechanism and Critical Starting Criterion of Wire Particle Firefly Movement under DC Electric Stress |
Chang Yanan1, Geng Qiuyu2, Hu Zhiying2, Li Qingmin1 |
1. State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power University Beijing 102206 China; 2. Beijing Key Lab of HV and EMC North China Electric Power University Beijing 102206 China |
|
|
Abstract In the DC gas-insulated switchgear and transmission lines (GIS/GIL), wire particles may exhibit a special firefly motion, namely, reverse motion without colliding with the ground electrode or suspended motion on the surface of the high-voltage electrode, which case is one of the principal factors affecting the insulation performance of the DC GIS/GIL. To clarify the physical mechanism of the firefly motion, a test platform was established to observe the firefly movement and measure the particle charge amount. The motion and charge characteristics of the wire particles at different voltage levels showed that, the polarity change of the particle charge due to the space charge near the wire particles was the key influential factor of the firefly movement, while the corona onset voltage of the wire particles on the electrode surface tended to be the critical voltage for the polarity change of the particle charge, as shown in Fig.1. The mechanism is applicable to the flake or spiral particles with low curvature radius, which generate similar space charge at the tip and change the charged polarity, leading to the firefly. Further, based on the photoionization model of the DC rod-plate gap corona, the corona onset voltage of the wire particles on the electrode surface was calculated, and the mathematical expression of the wire particle charge considering the corona voltage was fitted together with the measurement results. The charged wire particle motion model was thereby established considering the end concentration characteristics of the charge. Based on the proposed critical starting criterion of firefly, dynamic simulation of the linear particle flying motion was implemented as to obtain the onset electric field strength of firefly particles of different sizes in DC GIL. Then, the onset electric field strength of firefly particles with different sizes in DC GIL was calculated based on the charged wire particle motion model, as shown in Fig.2, and the validity of the calculation results is verified in real GIL. The obtained results indicated that, with the particle length increase, the particle radius decrease or the pressure decrease, the onset electric field strength of firefly particles decreased under positive and negative DC voltage. The onset field strength of a wire particle with 0.2mm diameter and 5 mm length in a 100kV GIL under 0.5MPa SF6 environment was 2.78MV/m for negative DC voltage and 4.93 MV/m for positive DC voltage. This study was based on the experiment in 110kV GIS, even though the particle motion characteristics at different voltage are numerically different from those at 110kV, the calculation method of particle motion characteristics are the same for different voltages. Therefore, the proposed research is suitable for DC GIL with different voltage levels, presents useful reference for DC GIL insulation design from the firefly particle suppression point of view.
|
Received: 26 March 2022
|
|
|
|
|
[1] 胡琦, 李庆民, 刘智鹏, 等. 基于表层梯度电导调控的直流三支柱绝缘子界面电场优化方法[J]. 电工技术学报, 2022, 37(7): 1856-1865. Hu Qi, Li Qingmin, Liu Zhipeng, et al.Interfacial electric field optimization of DC tri-post insulator based on gradient surface conductance regulation[J]. Transactions of China Electrotechnical Society, 2022, 37(7): 1856-1865. [2] 程涵, 魏威, Bilallqbal Ayubi, 等. 直流GIL中线形金属微粒电动力学行为研究[J]. 电工技术学报, 2021, 36(24): 5283-5293. Cheng Han, Wei Wei, Ayubi B, et al.Study on the electrodynamic behavior of linear metal particles in DC gas insulated transmission line[J]. Transactions of China Electrotechnical Society, 2021, 36(24): 5283-5293. [3] 张连根, 路士杰, 李成榕, 等. GIS中线形和球形金属微粒的运动行为和危害性[J]. 电工技术学报, 2019, 34(20): 4217-4225. Zhang Liangen, Lu Shijie, Li Chengrong, et al.Motor behavior and hazard of spherical and linear particle in gas insulated switchgear[J]. Transactions of China Electrotechnical Society, 2019, 34(20): 4217-4225. [4] Wang Jian, Li Qingmin, Liu Sihua, et al.Experimental studies of the air gap breakdown triggered by a free conducting particle in DC uniform field[C]//2016 IEEE International Conference on Dielectrics (ICD), Montpellier, France, 2016, 2: 1147-1150. [5] 李杰, 李晓昂, 吕玉芳, 等. 正弦振动激励下GIS内自由金属微粒运动特性[J]. 电工技术学报, 2021, 36(21): 4580-4589, 4597. Li Jie, Li Xiaoang, Lü Yufang, et al.Motion characteristics of free metal particles in GIS under sinusoidal vibration[J]. Transactions of China Electrotechnical Society, 2021, 36(21): 4580-4589, 4597. [6] Khan Y, Sakai K I, Lee E K, et al.Motion behavior and deactivation method of free-conducting particle around spacer between diverging conducting plates under DC voltage in atmospheric air[J]. IEEE Transactions on Dielectrics and Electrical Insulation, 2003, 10(3): 444-457. [7] Techaumnat B, Huynh V Q, Hidaka K.Numerical analysis and experiments on the electromechanical behavior of wired-shape conducting particles[J]. IEEE Transactions on Magnetics, 2018, 54(3): 1-5. [8] 王健, 李庆民, 李伯涛, 等. 直流GIL中自由线形金属微粒的运动与放电特性[J]. 中国电机工程学报, 2016, 36(17): 4793-4800. Wang Jian, Li Qingmin, Li Botao, et al.Motion and discharge behavior of the free conducting wire-type particle within DC GIL[J]. Proceedings of the CSEE, 2016, 36(17): 4793-4800. [9] Cooke C M, Wootton R E, Cookson A H.Influence of particles on AC and DC electrical performance of gas insulated systems at extra-high-voltage[J]. IEEE Transactions on Power Apparatus and Systems, 1977, 96(3): 768-777. [10] 魏威. 直流GIL电极表面纳米复合薄膜对放电及微粒的综合抑制机理研究[D]. 济南: 山东大学, 2020. [11] Hama H, Okabe S.Factors dominating dielectric performance of real-size gas insulated system and their measures by dielectric coatings in SF6 and potential gases[J]. IEEE Transactions on Dielectrics and Electrical Insulation, 2013, 20(5): 1737-1748. [12] 常亚楠, 王健, 李庆民, 等. 交直流气体绝缘管道输电装备微粒污染治理措施研究进展[J]. 高压电器, 2021, 57(10): 91-100, 110. Chang Yanan, Wang Jian, Li Qingmin, et al.Research progress of particle contamination suppression measures in AC and DC gas-insulated transmission equipment[J]. High Voltage Apparatus, 2021, 57(10): 91-100, 110. [13] 孙秋芹, 罗宸江, 王峰, 等. 直流GIL导体表面金属颗粒跳跃运动特性研究[J]. 电工技术学报, 2018, 33(22): 5206-5216. Sun Qiuqin, Luo Chenjiang, Wang Feng, et al.Jumping characteristics of metal particle on the surface of DC gas insulated transmission line conductor[J]. Transactions of China Electrotechnical Society, 2018, 33(22): 5206-5216. [14] Sakai K, Labrado Abella D, Suehiro J, et al.Charging and behavior of a spherically conducting particle on a dielectrically coated electrode in the presence of electrical gradient force in atmospheric air[J]. IEEE Transactions on Dielectrics and Electrical Insulation, 2002, 9(4): 577-588. [15] Wohlmuth M.Motion and discharges of free metallic particles[C] //8th International Symposium on High Voltage Engineering, Yokohama, 1993: 115-119. [16] 张乔根, 游浩洋, 马径坦, 等. 直流电压下SF6中自由线形导电微粒运动特性[J]. 高电压技术, 2018, 44(3): 696-703. Zhang Qiaogen, You Haoyang, Ma Jingtan, et al.Motion behavior of free conducting wire-type particles in SF6 gas under DC voltage[J]. High Voltage Engineering, 2018, 44(3): 696-703. [17] Wenger P, Beltle M, Tenbohlen S, et al.Combined characterization of free-moving particles in HVDC-GIS using UHF PD, high-speed imaging, and pulse-sequence analysis[J]. IEEE Transactions on Power Delivery, 2019, 34(4): 1540-1548. [18] Abdel-Salam M, Weiss P, Lieske B.Discharges in air from point electrodes in the presence of dielectric plates-experimental results[J]. IEEE Transactions on Electrical Insulation, 1992, 27(2): 309-319. [19] Khan Y, Oda A, Okabe S, et al.Wire particle motion behavior and breakdown characteristics around different shaped spacers within diverging air gap[J]. IEEJ Transactions on Power and Energy, 2003, 123(11): 1288-1295. [21] Parekh H, Srivastava K D. Effect of avalanche space charge field on the calculation of corona onset voltage[J]. IEEE Transactions on Electrical Insulation, 1979, EI-14(4): 181-192. [22] Natsuume D, Inami K, Hama H, et al.Development of numerical computational model for metallic wire particles' behavior in GIS for the estimation of the partial discharge-free allowable maximum flight height[J]. IEEJ Transactions on Power and Energy, 2004, 124(4): 634-642. |
|
|
|