Effects of Moisture Contents on Electrical Treeing Process in Glass Fiber Reinforced Epoxy Resin

被引:0
作者
Li J. [1 ]
Zhao R. [1 ,2 ]
Chen Y. [1 ]
Li T. [3 ]
Du B. [1 ]
机构
[1] School of Electrical and Information Engineering, Tianjin University, Tianjin
[2] State Grid Shandong Zibo Power Supply Bureau, Zibo
[3] State Grid Hebei Electric Power Research Institute, Shijiazhuang
来源
Diangong Jishu Xuebao/Transactions of China Electrotechnical Society | 2023年 / 38卷 / 05期
关键词
electrical tree; glass fiber reinforced epoxy resin (GFRP); Insulation pull rod; moisture content;
D O I
10.19595/j.cnki.1000-6753.tces.221441
中图分类号
学科分类号
摘要
Insulating pull rod is a key component of circuit breaker and disconnector of gas insulated metal enclosed switchgear (GIS), which is used to transfer movement from the grounding part to the high voltage part. It needs to withstand the recovery overvoltage and frequent mechanical operation, which puts forward high requirements on the comprehensive performance of the glass fiber reinforced epoxy resin (GFRP) composite. However, many internal breakdown and disassembly failures of insulation rods occurred in recent years, which seriously threaten the reliability of power equipment. In this paper, the influence of moisture content on the electrical tree growth characteristics of GFRP was studied. Combined with the dielectric properties and the hydrolysis characteristics of GFRP with different moisture contents, the mechanism of the electrical treeing process of GFRP was explained from the perspective of electric field distortion and insulation degradation. (1) Based on the relationship between moisture content and exposure time, it is verified that the moisture diffusion behavior in epoxy resin and GFRP composites conforms to the free diffusion Fick model. (2) When the pure epoxy resin absorbs moisture, the number of electrical tree channels increased and the color gradually deepened. In details, the growth rate of electrical tree length first increased and then decreased. Moreover, the expansion coefficient and the growth angle of electrical tree decreased and then increased, and the deterioration damage area gradually increased, indicating that electrical tree is more likely to grow along the vertical electric field direction with the increase of moisture content in the sample. (3) When the GFRP absorbs moisture, the number of electrical tree channels increases. In addition, the electrical tree will also grow along the interface perpendicular to the electric field direction. The growth rate of electrical tree length decreases first and then increases, while the growth rate and the growth angle of electrical tree also gradually increases. (4) It is found that when the moisture content in epoxy resin and GFRP exceeds 0.08% and 0.1% respectively, the deterioration of electrical tree significantly enhanced, which provided a basis for moisture control during the test, transportation and assembly of insulating pull rod. The fiber-epoxy interface may have defects of varying degrees due to hydrolysis and wet mismatch stress, and the moisture gradient diffusion further causes local electric field concentration, which aggravates the deterioration of GFRP. © 2023 Chinese Machine Press. All rights reserved.
引用
收藏
页码:1166 / 1176and1189
相关论文
共 29 条
[1]  
Zhang Liang, He Cong, Guo Ruochen, Et al., Research on effectiveness of lightning impulses with different parameters for detecting protrusion defects in GIS, IEEE Transactions on Dielectrics and Electrical Insulation, 27, 4, pp. 1354-1362, (2020)
[2]  
Li Jin, Zhao Renyong, Du Boxue, Et al., Research progress of nondestructive detection methods for defects of electrical epoxy insulators, Transactions of China Electrotechnical Society, 36, 21, pp. 4598-4607, (2021)
[3]  
Zheng Shusheng, Wu Shiyou, Detection study on propagation characteristics of partial discharge optical signal in GIS, IEEE Transactions on Instrumentation and Measurement, 70, pp. 1-12, (2021)
[4]  
Chen Yun, Zhang Pengfei, Cui Boyuan, Et al., Application status of insulation pull rod for 1 100 kV GIS circuit breaker, High Voltage Engineering, 45, 9, pp. 2699-2706, (2019)
[5]  
Zhao R Y, Li J, Chen Y, Et al., Defects detection of high voltage insulation pull rod based on ultrasonic wave method, 2020 IEEE International Conference on High Voltage Engineering and Application, pp. 1-4, (2020)
[6]  
Tao Fengbo, Wang Shuai, Jia Yongyong, Et al., Method of on-site tests for the withstand voltage of ultra-high-voltage GIS lightning impulse, High Voltage Engineering, 44, 12, pp. 3936-3943, (2018)
[7]  
Zhang Zhuo, Yang Wei, Yan Bingyue, Et al., Bubble defect simulation and technique parameters optimization of resin impregnated fiber for high voltage insulated pull rod, Insulating Materials, 53, 4, pp. 89-94, (2020)
[8]  
(2021)
[9]  
Gao Yanfeng, Liang Xidong, Liu Yingyan, Et al., Effect of electrical stress on glass fiber reinforced polymer used in high voltage composite insulator under wet environment, Composites Science and Technology, 155, pp. 151-159, (2018)
[10]  
Li Sheng, Tsang H H, Cheng Yongfeng, Et al., Seismic testing and modeling of cylindrical electrical equipment with GFRP composite insulators, Composite Structures, 194, pp. 454-467, (2018)