Novel Method for Electric Field Calculation Considering the Thickness of Contaminant Layer on the Surface of Composite Insulator
Wang Feng1,2, Liao Pingjun1, Huang Jun3, Luo Yong3, Xiao Yunjun3
1. School of Electrical and Information Engineering Hunan University Changsha 410082 China; 2. State Key Laboratory of Electrical Insulation and Power Equipment Xi’an Jiaotong University Xi’an 710049 China; 3. State Grid Zhuzhou Power Supply Company Zhuzhou 412000 China
Abstract:To study the mechanism of composite insulator pollution flashover, electric field analysis of the polluted composite insulators is required. However, the thickness of the contamination layer is only a fraction of millimeter that is much smaller than the size of insulator itself. Consequently, neither the finite element method nor boundary element method can solve such field problems with multiple scales at present. Therefore, This paper proposes a new method to calculate the surface electric field of polluted insulator based on the digital image processing. First, binary image processing is applied to the image of insulator with size m×n, and regional meshing is realized at each the pixel unit. Meanwhile, a mathematical model of impedance is established based on pixel unit. Then the node admittance matrix of size (m×n)×(m×n) is formed. The distribution of surface electric field of polluted insulator is calculated by electrical network analysis using node voltage method. The example shows that, compared with the existing algorithms, this method has significant advantages and improved effectiveness for modeling filthy layer which revealed contamination mechanism of composite insulator surface flashover, corona discharge, etc.
汪沨, 廖平军, 黄俊, 罗勇, 肖运军. 含污秽薄层的高压复合绝缘子表面电场计算新方法[J]. 电工技术学报, 2016, 31(10): 77-84.
Wang Feng, Liao Pingjun, Huang Jun, Luo Yong, Xiao Yunjun. Novel Method for Electric Field Calculation Considering the Thickness of Contaminant Layer on the Surface of Composite Insulator. Transactions of China Electrotechnical Society, 2016, 31(10): 77-84.
[1] 李晓峰, 李正瀛, 陈俊武. 提高线路绝缘子防污闪及抗泄露性能的新方法[J]. 电网技术, 2001, 25(10): 69-72. Li Xiaofeng, Li Zhengying, Chen Junwu. A new method for improving flashover and leakage chara- cteries of line insulator[J]. Power System Technology, 2001, 25(10): 69-72. [2] 孙才新, 顾乐观, 谢军, 等. 染污绝缘子沿面电场分布与局部电弧发展的关系[J]. 中国科学A辑, 1991, 21(10): 1113-1120. Sun Caixin, Gu Leguan, Xie Jun, et al. Relationship between surface electric field distribution and local arc development of polluted insulator[J]. Science in China (Series A: Mathematics), 1991, 21(10): 1113- 1120. [3] 张建辉, 顾乐观, 孙才新, 等. 染污支柱绝缘子沿面电场分布与污秽闪络的关系[J]. 电工技术学报, 1993, 18(4): 41-45, 63. Zhang Jianhui, Gu Leguan, Sun Caixin, et al. Rela- tionship between pollution flashover and surface electrical field of polluted post insulators[J]. Transa- ctions of China Electrotechnical Society, 1993, 18(4): 41-45, 63. [4] 张志劲, 蒋兴良, 孙才新, 等. 染污绝缘子串直流污闪放电模型及验证[J]. 电工技术学报, 2009, 24(4): 36-41. Zhang Zhijin, Jiang Xingliang, Sun Caixin, et al. DC pollution flashover model and its validation of polluted insulator strings[J]. Transactions of China Electrotechnical Society, 2009, 24(4): 36-41. [5] Xu G, McGrath P B. Electrical and thermal analysis of polymer insulator under contaminated surface conditions[J]. IEEE Transactions on Dielectrics and Electrical Insulation, 1996, 3(2): 289-298. [6] Asenjo S E, Morales O N, Valdenegro E A. Solution of low frequency complex fields in polluted insulators by means of the finite element method[J]. IEEE Transactions on Dielectrics and Electrical Insulation, 1997, 4(1): 10-16. [7] Chakravorti S, Mukherjee P K. Power frequency and impulse field calculation around a HV insulator with uniform or nonuniform surface pollution[J]. IEEE Transactions on Dielectrics and Electrical Insulation, 1993, 28(1): 43-53. [8] 韩长伟. 电气装备中电场数值计算的优化模拟电荷法[D]. 沈阳: 沈阳工业大学, 2006. [9] Que Weiguo, Sebo S A. Electric field and potential distribution along non-ceramic insulator with water droplets[C]//Electrical Insulation Conference and Elecrical Manufacturing & Coil Winding Conference Proceedings, Cincinnati, OH, 2001: 441-444. [10] 孙即祥. 数字图像处理[M]. 石家庄: 河北教育出版社, 1993. [11] 薛雷, 李维朝, 孙强, 等. 基于数字图像像素单元建立准三维FLAC3D模型[J]. 岩土力学, 2010, 31(6): 2001-2005. Xue Lei, Li Weichao, Sun Qiang, et al. Quasi-3D FLAC3D model generation based on pixel units of digital image[J]. Rock and Soil Mechanics, 2010, 31(6): 2001-2005. [12] 姚东来, 吴银忠. 无规电阻网络的等效电阻[J]. 大学物理, 2003, 22(3): 9-11. Yao Donglai, Wu Yinzhong. The equivalent resi- stance of random resistor networks[J]. College Phy- sics, 2003, 22(3): 9-11. [13] 韩社教, 马西奎, 戴栋. 有限元—解析结合解法在无界轴对称静电场问题数值解中的应用[J]. 电工技术学报, 2001, 16(5): 1-5. Han Shejiao, Ma Xikui, Dai Dong. Applications of hybrid FEM-analytic approach in unboundary axisymmetrical electrostatic field computation[J]. Transactions of China Electrotechnical Society, 2001, 16(5): 1-5. [14] 李和明, 芦杉, 高强, 等. 绝缘子污秽的毫米波辐射测量建模与计算[J]. 高压电器, 2009, 24(6): 172-177. Li Heming, Lu Shan, Gao Qiang, et al. Modeling and calculating of millimeter wave radiation measurement for insulator contamination[J]. High Voltage Appar- atus, 2009, 24(6): 172-177. [15] 项阳, 郭洁, 温定筠. 污秽潮湿状态下有机复合绝缘子周围电场分布研究[J]. 南方电网技术, 2010, 4(1): 36-40. Xiang Yang, Guo Jie, Wen Dingjun. Study on electric around transmission line composite insulators under polluted and wet condition[J]. Southern Power System Technology, 2010, 4(1): 36-40. [16] Corur R S, Karady G G,Jagota A, et al. Aging in sillicone rubbre used for outdoor insulation[J]. IEEE Transactions on Power Delivery, 1992, 7(2): 525- 531. [17] 张福林. 复合绝缘子外绝缘基材硅橡胶表面的憎水性和憎水迁移性机理分析[J]. 华北电力技术, 1999, 1(1): 19-21. Zhang Fulin. Analysis on surface hydrophobicity of external insulaling basic material silicon rubber of composite insulator and it's ion migration mecha- nism[J]. North China Electric Power, 1999, 1(1): 19-21. [18] 徐志钮, 律方成, 李和明. 分离水珠对支柱绝缘子电场分布的影响[J]. 高电压技术, 2010, 36(9): 2278-2284. Xu Zhiniu, Lü Fangcheng, Li Heming. Influence of separated globules on post insulator electric field distribution[J]. High Voltage Engineering, 2010, 36(9): 2278-2284. [19] 王仲奕, 王琪, 陈青. 复合绝缘子绝缘子憎水性表面水滴的电场特性分析[J]. 高压电器, 2009, 45(6): 5-11. Wang Zhongyi, Wang Qi, Chen Qing. Electric fied analysis of water droplet on hydrophobic surface of polymer insulator[J]. High Voltage Apparatus, 2009, 45(6): 5-11.