Mechanical and Electrical Performance Improvement and Process Optimization of Domestic UHV Large Tonnage Suspension Porcelain Insulator
Li Qun1, Gao Song1, Yang Shengzhe2, Hu Qinran2, Jiang Naisong2, Wu Zaijun2
1. State Grid Jiangsu Electric Power Company Research Institute Nanjing 211103 China; 2. School of Electrical Engineering Southeast University Nanjing 211189 China
Abstract：The comprehensive construction of ultra-high voltage projects require the guarantee of ultra-high voltage large-tonnage insulators. However, with the increase of service life, domestic ultra-high voltage and large tonnage insulators of 400 kN in operation frequently experience deterioration. In recent years, multiple incidents of porcelain insulator head breakage in ultra-high voltage AC and DC projects have shown that there are still blind spots in the design of insulator head structure, materials, and other aspects. Therefore, in response to the deterioration problem of ultra-high voltage insulators, this paper proposes improvement measures from three aspects: insulator head structure, insulator preform formula, and insulator production process to enhance their electromechanical performance. Firstly, the finite element analysis software Ansys was used to analyze the mechanical characteristics and maximum field strength of the head of ultra-high voltage large tonnage suspension porcelain insulators. Based on the equilibrium equation, geometric equation, and constitutive equation of the insulator model, this paper derived the mechanical distribution and deformation of insulators under mechanical stress. The optimal structural parameters for the head of ultra-high voltage and large-tonnage porcelain insulators were determined by observing the variation trend of stress at the most easily fractured part of the insulator with the wall thickness, top thickness, and sand height of the insulator head. By jointly solving Maxwell's equations and partial differential equations of the electric field, the distribution of the field strength at the insulator head was obtained, and the trend of the maximum field strength at the insulator head changing with the wall thickness, top thickness, outer angle, inner angle, and sand height of the insulator head was obtained. Secondly, this article has optimized and adjusted the formula of insulator preform and head glaze. By controlling the particle size in the raw material for insulator preparation, the adverse effect of coarse particles above 15 μm on the uniformity of product structure was eliminated. By increasing the crystal phase content in the insulator matrix formula, the porosity on the surface of the insulator ceramic body was reduced, making up for the defect of large dispersion of the insulator ceramic body. Meanwhile, this paper adopted the process of separately glazing the insulator head and umbrella surface, and used the optimized head glaze formula to enhance the mechanical strength of the insulator head. In addition, based on multiple experiments, this paper proposed optimization measures for the three steps of insulator sand grinding, glazed sand coating, and burning. By comparing the bending strength of the test strips prepared with one and two-step feeding schemes in the sand grinding process, it is concluded that the two-step feeding scheme has better mechanical properties of the ceramic body. By precoating the sand particles with a layer of glaze, the gap between the porcelain embryo and the sand was filled, and the bonding strength between the porcelain and the sand was enhanced. At the same time, based on considerable experiments, this paper has adjusted the heating rates of the three stages in the sintering process of alumina ceramics, ensuring product production quality while reducing production energy consumption. Finally, electromechanical failure load tests manifest that the mechanical and electrical failure performance of the optimized ultra-high voltage large tonnage insulators was significantly improved by about 16.5% than original insulators.
李群, 高嵩, 杨生哲, 胡秦然, 姜乃松, 吴在军. 国产特高压大吨位悬式瓷绝缘子机电性能提升与工艺优化方法[J]. 电工技术学报, 2023, 38(19): 5304-5315.
Li Qun, Gao Song, Yang Shengzhe, Hu Qinran, Jiang Naisong, Wu Zaijun. Mechanical and Electrical Performance Improvement and Process Optimization of Domestic UHV Large Tonnage Suspension Porcelain Insulator. Transactions of China Electrotechnical Society, 2023, 38(19): 5304-5315.
[1] 董飞飞, 李喜来, 王勇, 等. 我国特高压工程发展历程及发展建议[J]. 中国工程咨询, 2023(6): 42-45. [2] 邓学群, 张悦, 魏东, 等. 1000 kV特高压输电线路电磁环境影响预测与评价[J]. 能源与节能, 2023(4): 99-102. Deng Xuequn, Zhang Yue, Wei Dong, et al.Prediction and evaluation of electromagnetic environment impact of 1 000 kV UHV transmission line[J]. Energy and Energy Conservation, 2023(4): 99-102. [3] Hu Yi, Liu Kai, Wu Tian, et al.Key technology research and application of live working technology on EHV/UHV transmission lines in China[C]//2014 International Conference on Power System Technology, Chengdu, China, 2014: 2299-2309. [4] 郭瑞兴, 赵洪远, 段纲, 等. 大吨位绝缘子配套金具研究[J]. 山东电力技术, 2018, 45(9): 38-42. Guo Ruixing, Zhao Hongyuan, Duan Gang, et al.Research of metal fittings of long tonnage insulators[J]. Shandong Electric Power, 2018, 45(9): 38-42. [5] 丁昊晖, 任鹏宇, 张峻峰, 等. 一种基于毫米波FMCW雷达的绝缘子内部缺陷识别方法: CN113310942A[P].2021-08-27. [6] 褚双伟, 华奎, 卢明, 等. 特高压线路大吨位绝缘子挂网运行情况分析[J]. 广东电力, 2018, 31(4): 27-33. Chu Shuangwei, Hua Kui, Lu Ming, et al.Analysis on operation of large tonnage insulators on UHV transmission lines[J]. Guangdong Electric Power, 2018, 31(4): 27-33. [7] 杨威, 白永祥, 华奎, 等. 国内特高压线路大吨位绝缘子使用情况调查[J]. 电瓷避雷器, 2018(5): 241-247. Yang Wei, Bai Yongxiang, Hua Kui, et al.Investigation on the use of large tonnage insulators in UHV transmission lines[J]. Insulators and Surge Arresters, 2018(5): 241-247. [8] 李岳, 周路遥, 李特, 等. 500kV线路瓷绝缘子雷击断串故障分析[J]. 浙江电力, 2020, 39(4): 17-21. Li Yue, Zhou Luyao, Li Te, et al.Fault analysis for lightning strike-caused string fracture of 500kV line porcelain insulators[J]. Zhejiang Electric Power, 2020, 39(4): 17-21. [9] 李进, 赵仁勇, 杜伯学, 等. 电工环氧绝缘件缺陷无损检测方法研究进展[J]. 电工技术学报, 2021, 36(21): 4598-4607. Li Jin, Zhao Renyong, Du Boxue, et al.Research progress of nondestructive detection methods for defects of electrical epoxy insulators[J]. Transactions of China Electrotechnical Society, 2021, 36(21): 4598-4607. [10] 杨建伟. 绝缘子劣化的认识[J]. 农村电工, 2016, 24(11): 24. [11] 郑兴益, 薛志岗, 朱军. 95氧化铝绝缘子烧成工艺的研究[J]. 江苏陶瓷, 2018, 51(1): 25-27, 30. [12] 司晓闯, 齐小乔, 王彩君, 等. 复合绝缘子用胶装剂性能优化研究[J]. 河南科技, 2021, 40(8): 129-131. Si Xiaochuang, Qi Xiaoqiao, Wang Caijun, et al.Study on performance optimization of epoxy resin binder for composite insulator[J]. Henan Science and Technology, 2021, 40(8): 129-131. [13] 缪春辉, 王万里, 王若民, 等. 盘型悬式绝缘子钢脚材料热处理工艺优化及其低周疲劳性能[J]. 材料热处理学报, 2021, 42(8): 99-108. Miao Chunhui, Wang Wanli, Wang Ruomin, et al.Heat treatment process optimization and low-cycle fatigue performance of disk suspension insulator pin steels[J]. Transactions of Materials and Heat Treatment, 2021, 42(8): 99-108. [14] 周学明, 尹骏刚, 胡丹晖, 等. 圆柱头盘形悬式瓷绝缘子钢脚结构优化分析[J]. 电瓷避雷器, 2022(2): 159-166. Zhou Xueming, Yin Jungang, Hu Danhui, et al.Pin structure optimization of cylindrical head suspension porcelain insulator[J]. Insulators and Surge Arresters, 2022(2): 159-166. [15] 郑奇凯, 孙阔腾, 黄松强, 等. 防冰涂层材料及电力材料防覆冰应用的研究进展[J]. 表面技术, 2021, 50(12): 282-293. Zheng Qikai, Sun Kuoteng, Huang Songqiang, et al.Research progress of anti-icing coating materials and its applications in the protection of power materials[J]. Surface Technology, 2021, 50(12): 282-293. [16] 李剑, 王湘雯, 黄正勇, 等. 超疏水绝缘涂层制备与防冰、防污研究现状[J]. 电工技术学报, 2017, 32(16): 61-75. Li Jian, Wang Xiangwen, Huang Zhengyong, et al.Research of preparation, anti-icing and anti-pollution of super hydrophobic insulation coatings[J]. Transactions of China Electrotechnical Society, 2017, 32(16): 61-75. [17] 许文杰, 黄正勇, 李剑, 等. 碳化硅改性超疏水涂层协同增强直流沿面闪络性能及机理研究[J]. 电工技术学报, 2023, 38(9): 2480-2490. Xu Wenjie, Huang Zhengyong, Li Jian, Wang et al. Study on the synergistic enhancement of the DC surface flashover performance and the mechanism of the superhydrophobic coating modified by silicon carbide[J]. Transactions of China Electrotechnical Society, 2023, 38(9): 2480-2490. [18] Wang Feipeng, Wen Gang, Fan Fan, et al.Turn hydrophobic to superhydrophobic of composite insulators by surface fluorination[C]//2016 IEEE International Conference on High Voltage Engineering and Application (ICHVE), Chengdu, China, 2016: 1-4. [19] 王靖瑞, 李庆民, 刘衡, 等. 纳米复合涂层对微米级金属粉尘吸附行为的抑制作用[J]. 电工技术学报, 2022, 37(12): 3172-3182. Wang Jingrui, Li Qingmin, Liu Heng, et al.Suppression effect of nanocomposite coating on the adsorption behavior of micron-scale metal dust[J]. Transactions of China Electrotechnical Society, 2022, 37(12): 3172-3182. [20] Kumar S M, Kalaivani L.Electric field distribution analysis of 110 kV composite insulator using Finite Element Modeling[C]//2014 International Conference on Circuits, Power and Computing Technologies [ICCPCT-2014], Nagercoil, India, 2015: 136-141. [21] 杨钊, 董瑞, 王莉, 等. 储能系统用母线排电场及静力学仿真分析[J]. 电气技术, 2022, 23(3): 63-69. Yang Zhao, Dong Rui, Wang Li, et al.Electric field and statics simulation analysis of busbar for energy storage system[J]. Electrical Engineering, 2022, 23(3): 63-69. [22] 张语桐, 吴泽华, 徐家忠, 等. 特高压GIS用单支撑绝缘子绝缘结构优化设计[J]. 电工技术学报, 2023, 38(1): 258-269. Zhang Yutong, Wu Zehua, Xu Jiazhong, et al.Optimization design of insulation structure for post insulator in UHVAC GIS[J]. Transactions of China Electrotechnical Society, 2023, 38(1): 258-269. [23] 李鹏, 范建斌, 李光范, 等. 1000kV级特高压交流线路绝缘子串电位分布计算和均压环设计[J]. 中国电力, 2006, 39(10): 33-36. Li Peng, Fan Jianbin, Li Guangfan, et al.Electric field distribution calculation and grading ring design of insulators string for 1000 kV UHVAC lines[J]. Electric Power, 2006, 39(10): 33-36. [24] 国家能源局. 高压直流线路用盘形悬式复合瓷或玻璃绝缘子串元件: DL/T 1471—2015[S]. 北京: 中国电力出版社, 2015.
2023, Vol. 38 
