温度梯度对直流盆式绝缘子表面电荷积聚特性的影响

doi:10.19595/j.cnki.1000-6753.tces.250827

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Abstract With the continuous development of the power grid scale and renewable energy, flexible high voltage direct current (HVDC) transmission technology has gained global wide attention. The DC gas insulated switchgear/transmission line (GIS/GIL) have advantages of low loss, large capacity, and easy grid interconnection, which become a key link in HVDC transmission systems. However, surface charge accumulation on basin insulators will degrade the interfacial insulation performance, posing a key technical challenge of insulation design. Under regular serving conditions, the current thermal effect will create high temperature in the central conductor, which generates radial temperature gradients across insulators. The temperature gradient significantly influences the insulator’s bulk conductivity distribution and surface charge accumulation, which may further reduce flashover voltage along the gas-solid interface. At present, few studies systematically examine how temperature gradients affect surface charge accumulation, which significantly hinders the insulation design of DC GIS/GIL under thermal gradients.
This study first constructed a surface charge measurement platform with controllable temperature gradient. It enabled the temperature difference (ΔT) between HV conductor and grounded electrode to be adjusted from 0°C to 63.4°C. Then the surface charge distributions were tested under positive DC voltage and various temperature gradients. The results showed that the temperature gradients did not alter the surface charge accumulation pattern. A bipolar-charge distribution appeared on insulator surface: positive charges concentrated between the HV and grounded electrodes, while negative charges mainly distributed near the grounded electrode. As ΔT increased from 0°C to 63.4°C, the distribution area of positive charges shrank gradually, with average density decreasing from 2.09 µC/m² to 1.05 µC/m². In contrast, the distribution area of negative charge expanded significantly, with average density rising from 2.39 µC/m² to 5.77 µC/m² (a 141% increase). Absolute maximum charge density increased from 8.21 µC/m² to 16.24 µC/m². These findings demonstrated that temperature gradients substantially enhanced surface charge accumulation on insulators.
To analyze how temperature gradients affect the dominant accumulation pathways of surface charge, a multi-physics field simulation model coupling electric, thermal, and gas flow fields was further developed. This model accounted for the temperature-dependent bulk conductivity of the insulator, as well as the charged particle’s diffusion, migration and recombination processes driven by the electric and flow fields in gas side. The results showed that under no and low temperature gradients, the bulk conductivity was small, resulting in a relatively small bulk conduction current, so the surface conduction current was the dominant accumulation pathway for positive charges. As the temperature gradient increased, the dominant accumulation pathway of positive charges gradually changed from surface conduction to bulk conduction due to the surge of insulator bulk conductivity. And the difference between bulk current and surface current became smaller, resulting in a reduction of positive charge density. The dominant accumulation pathway of negative charges was always surface conduction. The increase in temperature gradient caused the electric field near the ground electrode to surge from 1.05 kV/mm to 2.78 kV/mm, which led to a significant increase in the surface current and negative charge density near the grounded electrode.
Overall, large temperature gradients will cause an electric field surge near the grounded electrode, further aggravating the surface charge accumulation. This may result in a greater risk of flashover occurring along the gas-solid interface. Therefore, it is necessary to explore insulating materials with low temperature coefficients of bulk conductivity in DC GIS/GIL, which makes the electric field and surface charge accumulation to be reduced. Meanwhile, components such as shields and flanges in the vicinity of the grounded shell need to be particularly designed to maximally relax the electric field distortion.

Key words： DC GIS/GIL gas-solid interface charge accumulation temperature gradient electro-thermal coupling

Received: 18 May 2025

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	Han Pu
	Pan Cheng
	Ye Yuhan
	Qin Xiaoyu
	He Chuangwei

Cite this article:

Han Pu,Pan Cheng,Ye Yuhan等. Effect of Temperature Gradient on Surface Charge Accumulation Characteristics of DC Basin Insulators[J]. Transactions of China Electrotechnical Society, 2026, 41(9): 3157-3169.

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https://dgjsxb.ces-transaction.com/EN/10.19595/j.cnki.1000-6753.tces.250827 OR https://dgjsxb.ces-transaction.com/EN/Y2026/V41/I9/3157

[1] 欧阳金鑫, 陈纪宇, 李昂, 等. 兼顾直流电压安全与无功支撑的柔性直流输电故障穿越控制[J]. 电工技术学报, 2024, 39(19): 6129-6144.
Ouyang Jinxin, Chen Jiyu, Li Ang, et al.Fault ride-through control method for VSC-HVDC balancing between DC voltage security and reactive power support[J]. Transactions of China Electrotechnical Society, 2024, 39(19): 6129-6144.
[2] 刘欣, 袁易, 王利桐, 等. 柔性直流输电系统三端口混合参数建模及其稳定性分析[J]. 电工技术学报, 2024, 39(16): 4968-4984.
Liu Xin, Yuan Yi, Wang Litong, et al.Three-port hybrid parameter modeling and stability analysis of MMC-HVDC system[J]. Transactions of China Electrotechnical Society, 2024, 39(16): 4968-4984.
[3] 李庆民, 王昌柱, 武文琪, 等. 直流GIS/GIL绝缘子沿面绝缘性能提升方法研究进展[J]. 高电压技术, 2025, 51(3): 987-1009.
Li Qingmin, Wang Changzhu, Wu Wenqi, et al.Advance in research of insulation performance enhancement methods along the surface of DC GIS/ GIL insulators[J]. High Voltage Engineering, 2025, 51(3): 987-1009.
[4] Zhang Boya, Ji Kai, Li Yixuan, et al.Surface charging characteristics of a real-sized DC GIS insulator in pressurized clean air as a feasible SF₆ alternative[J]. IEEE Transactions on Power Delivery, 2024, 39(4): 2149-2159.
[5] 毛诗壹, 潘成, 罗毅, 等. 基于混合Lanczos- Tikhonov算法的绝缘子表面电荷反演计算[J]. 电工技术学报, 2023, 38(7): 1921-1934.
Mao Shiyi, Pan Cheng, Luo Yi, et al.Inversion algorithm for surface charge on insulator based on hybrid Lanczos-Tikhonov algorithm[J]. Transactions of China Electrotechnical Society, 2023, 38(7): 1921-1934.
[6] Mao Shiyi, Pan Zijun, Ye Yuhan, et al.Electric-field- induced assists fabrication of micro-SiC/Epoxy coating with low additive amount to improve surface insulating performance of HVDC insulator[J]. Composites Science and Technology, 2024, 255: 110696.
[7] 杜伯学, 姚航, 梁虎成, 等. 时变温差工况下直流GIL/GIS盆式绝缘子动态电场畸变抑制[J]. 电工技术学报, 2024, 39(9): 2851-2859.
Du Boxue, Yao Hang, Liang Hucheng, et al.Electric field relaxation of basin spacer under variable temperature gradient in DC-GIL/GIS[J]. Transactions of China Electrotechnical Society, 2024, 39(9): 2851-2859.
[8] 王哲铭, 潘越, 张磊, 等. 直流GIL气-固界面电荷调控的影响因素分析[J]. 中国电机工程学报, 2021, 41(20): 7177-7193.
Wang Zheming, Pan Yue, Zhang Lei, et al.Analysis of charge tailoring techniques for DC GIL gas-solid interface charges[J]. Proceedings of the CSEE, 2021, 41(20): 7177-7193.
[9] Hering M, Gremaud R, Speck J, et al.Flashover behaviour of insulators with inhomogeneous temperature distribution in gas insulated systems under DC voltage stress[C]//2014 ICHVE International Conference on High Voltage Engineering and Application, Poznan, Poland, 2014: 1-4.
[10] Zhang Lei, Tang Deyue, Yu Di, et al.Temperature- dependent surface charge accumulation for vertical and horizontal HVDC GIL[J]. IEEE Transactions on Dielectrics and Electrical Insulation, 2023, 30(4): 1868-1876.
[11] Yan Wu, Li Chuanyang, Lei Zhipeng, et al.Surface charging on HVDC spacers considering time-varying effect of temperature and electric fields[J]. IEEE Transactions on Dielectrics and Electrical Insulation, 2019, 26(4): 1316-1324.
[12] Du Boxue, Liang Hucheng, Li Jin, et al.Electrical field distribution along SF₆/N₂ filled DC-GIS/GIL epoxy spacer[J]. IEEE Transactions on Dielectrics and Electrical Insulation, 2018, 25(4): 1202-1210.
[13] Ma Guoming, Zhou Hongyang, Lu Shijie, et al.Effect of material volume conductivity on surface charges accumulation on spacers under DC electro-thermal coupling stress[J]. IEEE Transactions on Dielectrics and Electrical Insulation, 2018, 25(4): 1211-1220.
[14] 何顺, 郑易谷, 林川杰, 等. 温度梯度下电荷行为与直流沿面闪络的关联性[J]. 高电压技术, 2020, 46(10): 3597-3604.
He Shun, Zheng Yigu, Lin Chuanjie, et al.Relation between charge behavior and DC surface flashover under temperature gradient[J]. High Voltage Engineering, 2020, 46(10): 3597-3604.
[15] 胡琦, 李庆民, 刘智鹏, 等. 温度梯度下直流GIL三支柱绝缘子电荷积聚对电场分布的影响分析[J]. 电工电能新技术, 2021, 40(7): 20-27.
Hu Qi, Li Qingmin, Liu Zhipeng, et al.Impact analysis of charge accumulation on electric field distribution of DC GIL tri-post insulator under temperature gradients[J]. Advanced Technology of Electrical Engineering and Energy, 2021, 40(7): 20-27.
[16] Li Chuanyang, Hu Jun, Lin Chuanjie, et al.The potentially neglected culprit of DC surface flashover: electron migration under temperature gradients[J]. Scientific Reports, 2017, 7(1): 3271.
[17] 周宏扬, 马国明, 赵书静, 等. 温度对直流GIL绝缘子电荷积聚特性的影响[J]. 中国电机工程学报, 2016, 36(24): 6675-6681, 6920.
Zhou Hongyang, Ma Guoming, Zhao Shujing, et al.Effect of temperature on charge accumulation on insulator in DC-GIL[J]. Proceedings of the CSEE, 2016, 36(24): 6675-6681, 6920.
[18] Ma Guoming, Zhou Hongyang, Liu Shupin, et al.Measurement and simulation of charge accumulation on a disc spacer with electro-thermal stress in SF₆ gas[J]. IEEE Transactions on Dielectrics and Electrical Insulation, 2018, 25(4): 1221-1229.
[19] Liang Fangwei, Fan Xianhao, Hu Jun, et al.Surface charging physics of the basin insulator in ±320 kV gas-insulated transmission lines[J]. IEEE Transactions on Dielectrics and Electrical Insulation, 2024, 31(3): 1654-1656.
[20] 李思庚, 李庆民, 王伟, 等. 电热协同老化应力下环氧树脂复合材料沿面闪络特性与数值模拟[J]. 电工技术学报, 2025, 40(13): 4045-4057.
Li Sigeng, Li Qingmin, Wang Wei, et al.Characterization and numerical simulation of epoxy resin composites flashed along the surface under electro-thermal co-aging stresses[J]. Transactions of China Electrotechnical Society, 2025, 40(13): 4045-4057.
[21] 潘子君, 潘成, 唐炬, 等. 基于图像复原技术与约束最小二乘方滤波器的绝缘子表面电荷反演算法[J]. 电工技术学报, 2021, 36(17): 3627-3638.
Pan Zijun, Pan Cheng, Tang Ju, et al.Inversion algorithm for surface charge on insulator based on image restoration technology and constrained least square filter[J]. Transactions of China Electrotechnical Society, 2021, 36(17): 3627-3638.
[22] Li Xiaolong, Zhang Guangkuo, Cao Chen, et al.Effects of volume and surface conductivity on the surface charge and electric field characteristics of the tri-post insulator in SF₆-filled ± 500 kV DC-GIL[J]. IET Generation, Transmission & Distribution, 2023, 17(1): 230-239.
[23] 罗传仙, 邱虎, 孙亚辉, 等. 直流电压下GIS盆式绝缘子表面电荷及电场分布特性仿真研究[J]. 高压电器, 2024, 60(3): 101-110.
Luo Chuanxian, Qiu Hu, Sun Yahui, et al.Simulation study on surface charge and electric field distribution characteristics of GIS insulating spacer under DC voltage[J]. High Voltage Apparatus, 2024, 60(3): 101-110.
[24] De Lorenzi A, Grando L, Pesce A, et al.Modeling of epoxy resin spacers for the 1 MV DC gas insulated line of ITER neutral beam injector system[J]. IEEE Transactions on Dielectrics and Electrical Insulation, 2009, 16(1): 77-87.
[25] Liang Hucheng, Du Boxue, Li Jin.Electric field regulation and parameter optimization of surface nonlinear conductivity spacer for 500 kV DC-GIL[J]. IEEE Transactions on Dielectrics and Electrical Insulation, 2020, 27(4): 1330-1338.
[26] Luo Yi, Tang Ju, Pan Zijun, et al.How temperature and pressure affect the electric field distribution in HVDC GIS/GIL: a numerical study[J]. IEEE Transactions on Dielectrics and Electrical Insulation, 2021, 28(4): 1334-1342.
[27] 贾博文, 王哲铭, 王耀港, 等. 考虑静态金属微粒下的直流GIL绝缘子表面电荷仿真: 微放电下的离散电荷斑[J]. 高电压技术, 2025, 51(3): 1080-1091.
Jia Bowen, Wang Zheming, Wang Yaogang, et al.Simulation of surface charge on DC GIL insulator in consideration of static metal particles: discrete charge spots under micro-discharge[J]. High Voltage Engineering, 2025, 51(3): 1080-1091.
[28] 张雨啸, 张磊, 唐忠. 外部环境温度与内部气压对HVDC GIL表面电荷积聚的影响[J]. 绝缘材料, 2024, 57(9): 80-87.
Zhang Yuxiao, Zhang Lei, Tang Zhong.Effect of external ambient temperature and internal gas pressure on surface charge accumulation of HVDC GIL[J]. Insulating Materials, 2024, 57(9): 80-87.
[29] 王超, 李文栋, 陈俊鸿, 等. 550 kV GIS盆式绝缘子小型化设计(三): 缩比结构验证[J]. 电工技术学报, 2023, 38(7): 1970-1981.
Wang Chao, Li Wendong, Chen Junhong, et al.Compact design of 550 kV basin-type spacer in gas insulated switchgear (part Ⅲ): downsized structure verification[J]. Transactions of China Electrotech-nical Society, 2023, 38(7): 1970-1981.