|
|
|
| Mechanical Performance Analysis and Research on New Methods for Online Non-Destructive Evaluation of Glass Fiber Reinforced Plastic Connectors in Converter Valves |
| Zhang Xinlong1, Zou Yansheng2, Cheng Li1, Tao Bo1, Liao Ruijin1 |
1. State Key Laboratory of Power Transmission Equipment Technology Chongqing University Chongqing 400044 China;
2. Electric Power Research Institute EHV Company of CSG Guangzhou 510530 China |
|
|
|
Abstract With the increase in operation time of high-voltage converter valves, there has been a significant issue of surface cracking observed in a large number of glass fiber reinforced plastic (GFRP) connectors. However, currently, there is limited research on the actual mechanism of GFRP connector cracking within converter stations, and the long-term mechanical performance remains unclear. Meanwhile, the assessment of its mechanical properties presently relies mainly on destructive offline testing, without the ability to accurately characterize its mechanical performance through online non-destructive testing methods. Acoustic emission (AE) methods enable real-time dynamic inspection of microcracks and represent a potential non-destructive testing method for evaluating the mechanical performance of GFRP equipment online. This paper investigates the cracking mechanism of GFRP connectors and employs acoustic emission technology to assess the residual mechanical strength of GFRP connectors. The results show that creep failure under long-term loading is the cause of physical damage to GFRP connectors; the evaluation mechanical performance of cracked GFRP connectors obtained through acoustic emission technology closely matches actual test results, with an error range of 1% to 3%.
Firstly, physical and chemical tests were conducted on both new and cracked GFRP connectors. The experimental results indicate that compared to the new GFRP connectors, the cracked ones do not exhibit significant chemical aging or thermal decomposition. However, they do present internal defects such as fiber breakage, matrix cracking, and fiber-matrix interface debonding, leading to a substantial decrease in mechanical performance. It was preliminarily confirmed that physical damage caused by mechanical stress is the primary reason for failure. Subsequently, a three-dimensional simulation model of the GFRP connectors was established using Ansys software. Simulation results indicate that under actual working conditions, the stress on the GFRP connectors is mainly concentrated at the actual crack locations, with the maximum stress reaching 47.3 MPa, exceeding their maximum load capacity (43.5 MPa), resulting in crack failure in that area. Additionally, the maximum stress exceeds 30% of the bending strength (122.3 MPa) of the GFRP connectors not yet in operation, meeting the premise of GFRP creep failure behavior, further validating that the cracking of GFRP connectors is caused by mechanical reasons. Finally, samples with different residual mechanical strengths were prepared through mechanical aging tests of varying durations. A weak acoustic signal detection platform was established, and the samples were subjected to acoustic emission loading tests using this platform.
The results of the acoustic emission loading tests show that there was no significant change in the residual mechanical strength of the samples before and after the tests, validating the non-destructive nature of acoustic emission detection method. Furthermore, under low-load conditions, the hit count rate increased approximately linearly with time, and the residual mechanical strength of the samples decreased linearly with the increase in hit count rate, with the slope and intercept of the negative linear relationship having an exponential relationship with the applied load. By utilizing the negative linear relationship between residual mechanical strength and hit count rate, the residual mechanical strength of cracked GFRP connectors can be quantitatively calculated. Compared to actual test values, the error range is only 1.4%~3.2%, indicating that acoustic emission detection technology is feasible for online evaluation of GFRP connectors.
|
|
Received: 05 March 2024
|
|
|
|
|
|
[1] 聂阳阳, 周文青, 赵一枫, 等. 换流阀PVDF冷却水管损伤漏水事故原因分析[J]. 广东电力, 2022, 35(9): 102-108.
Nie Yangyang, Zhou Wenqing, Zhao Yifeng, et al.Cause analysis of water leakage on the surface of PVDF cooling water pipe of converter valve[J]. Guangdong Electric Power, 2022, 35(9): 102-108.
[2] 李通, 刘鹏龙, 李宁瑞, 等. 垢层动态膜阻对换流阀冷却系统内均压电极动态沉积特性影响机理研究[J]. 电工技术学报, 2023, 38(7): 1695-1704.
Li Tong, Liu Penglong, Li Ningrui, et al.Study on the influence of the dynamic film resistance of scale layer on the dynamic deposition characteristics of grading electrodes in inner cooling system of converter calve[J]. Transactions of China Electrotechnical Society, 2023, 38(7): 1695-1704.
[3] 袁佳歆, 莫作权, 李旭哲, 等. 换流阀用阳极饱和电抗器研究综述[J]. 高电压技术, 2022, 48(12): 4829-4841.
Yuan Jiaxin, Mo Zuoquan, Li Xuzhe, et al.Review of anode saturable reactor for converter valve[J]. High Voltage Engineering, 2022, 48(12): 4829-4841.
[4] Yuan Jiaxin, Li Xuzhe, Mo Zuoquan, et al.Research on vibration of the reactor for HVDC thyristor protection[J]. Energy Reports, 2022, 8: 321-329.
[5] 刘云鹏, 来庭煜, 刘嘉硕, 等. 特高压直流换流阀饱和电抗器振动声纹特性与松动程度声纹检测方法[J]. 电工技术学报, 2023, 38(5): 1375-1389.
Liu Yunpeng, Lai Tingyu, Liu Jiashuo, et al.Vibration voiceprint characteristics and looseness detection method of UHVDC converter valve saturable reactor[J]. Transactions of China Electrotechnical Society, 2023, 38(5): 1375-1389.
[6] 乔新涵, 张志劲, 蒋正龙, 等. 10 kV复合避雷器组合绝缘子雷电冲击污闪特性及模型[J]. 电工技术学报, 2024, 39(21): 6932-6940.
Qiao Xinhan, Zhang Zhijin, Jiang Zhenglong, et al.Lightning impulse pollution flashover characteristics and model of 10 kV composite arrester combined insulator[J]. Transactions of China Electrotechnical Society, 2024, 39(21): 6932-6940.
[7] Zhang Pengning, Li Lin.Vibration of saturable reactor core used in HVDC converter valve system[J]. The Journal of Engineering, 2017, 2017(14): 2584-2590.
[8] 乔井彦, 李金柱, 张羲黄, 等. 环氧树脂玻璃钢的动静态拉伸力学特性[J]. 高压物理学报, 2023, 37(3): 29-38.
Qiao Jingyan, Li Jinzhu, Zhang Xihuang, et al.Dynamic and static tensile mechanical properties of glass fiber reinforced plastics[J]. Chinese Journal of High Pressure Physics, 2023, 37(3): 29-38.
[9] 刘贺晨, 胡如法, 刘云鹏, 等. 220 kV退役复合绝缘子芯棒整体回收再利用可行性研究[J]. 电工技术学报, 2024, 39(11): 3433-3443.
Liu Hechen, Hu Rufa, Liu Yunpeng, et al.Feasibility of the overall recycling of 220 kV retired composite insulator core rods[J]. Transactions of China Electro-technical Society, 2024, 39(11): 3433-3443.
[10] Lee B L, Holl M W.Effects of moisture and thermal cycling on in-plane shear properties of graphite fibre-reinforced cyanate ester resin composites[J]. Composites Part A: Applied Science and Manufacturing, 1996, 27(11): 1015-1022.
[11] 朱德举, 徐旭锋, 郭帅成, 等. 高温后玄武岩和玻璃纤维增强复合材料筋的力学性能[J]. 湖南大学学报(自然科学版), 2021, 48(7): 151-159.
Zhu Deju, Xu Xufeng, Guo Shuaicheng, et al.Mechanical properties of basalt and glass fiber reinforced polymer tendons after exposed to elevated temperatures[J]. Journal of Hunan University (Natural Sciences), 2021, 48(7): 151-159.
[12] Sodoke F K, Toubal L, Laperrière L.Hygrothermal effects on fatigue behavior of quasi-isotropic flax/ epoxy composites using principal component analysis[J]. Journal of Materials Science, 2016, 51(24): 10793-10805.
[13] 刘颖红林, 李伟, 蒋鹏, 等. 基于声发射检测的能量释放率预测多向复合材料层合板的分层机理[J]. 压力容器, 2023, 40(8): 1-11.
Liu Yinghonglin, Li Wei, Jiang Peng, et al.Prediction of delamination mechanism of multidirectional comp-osite laminates based on energy release rate in acoustic emission detection[J]. Pressure Vessel Technology, 2023, 40(8): 1-11.
[14] Caprino G, Teti R, de Iorio I. Predicting residual strength of pre-fatigued glass fibre-reinforced plastic laminates through acoustic emission monitoring[J]. Composites Part B: Engineering, 2005, 36(5): 365-371.
[15] 隋晓东, 吴凯文, 李烨, 等. 基于声发射技术的单丝复合材料界面性能研究[J]. 材料科学与工艺, 2020, 28(1): 53-59.
Sui Xiaodong, Wu Kaiwen, Li Ye, et al.Study on interfacial properties of single fiber composites by acoustic emission[J]. Materials Science and Technology, 2020, 28(1): 53-59.
[16] Oh K S, Han K S.Fatigue life modeling of short fiber reinforced metal matrix composites using mechanical and acoustic emission responses[J]. Journal of Composite Materials, 2013, 47(10): 1303-1310.
[17] 国家质量监督检验检疫总局, 中国国家标准化管理委员会. 纤维增强塑料弯曲性能试验方法: GB/T 1449—2005[S]. 北京: 中国标准出版社, 2005.
[18] 国家质量监督检验检疫总局、中国国家标准化管理委员会. 纤维增强塑料拉伸性能试验方法: GB/T 1447—2005[S]. 北京: 中国标准出版社, 2005.
[19] 刘红, 邝凡, 胡德桥. 硅橡胶复合绝缘子老化状态核磁共振与红外光谱对比分析研究[J]. 广东电力, 2023, 36(12): 121-126.
Liu Hong, Kuang Fan, Hu Deqiao.Nuclear magnetic resonance and infrared spectroscopy method for aging state of silicone rubber composite insulators[J]. Guangdong Electric Power, 2023, 36(12): 121-126.
[20] 卢明, 高超, 吴焱松, 等. 复合绝缘子脆性断裂与酥朽断裂差异性研究[J]. 高压电器, 2022, 58(6): 17-23.
Lu Ming, Gao Chao, Wu Yansong, et al.Study on difference between brittle fracture and decay? like fracture of composite insulator[J]. High Voltage Apparatus, 2022, 58(6): 17-23.
[21] 成立, 梅红伟, 王黎明, 等. 复合绝缘子用硅橡胶护套长时间老化特性及其影响因素[J]. 电网技术, 2016, 40(6): 1896-1902.
Cheng Li, Mei Hongwei, Wang Liming, et al.Study on long-term aging characteristics and impact factors for silicone rubber sheath of composite insulators[J]. Power System Technology, 2016, 40(6): 1896-1902.
[22] 王刚, 金智康, 宋俊杰, 等. 复合涂层对玻璃纤维增强尼龙6复合材料界面性能的影响[J]. 复合材料学报, 2023, 40(12): 6668-6680.
Wang Gang, Jin Zhikang, Song Junjie, et al.Effect of composite coating on interfacial properties of glass fiber reinforced polyamide 6 composites[J]. Acta Materiae Compositae Sinica, 2023, 40(12): 6668-6680.
[23] 初明越, 阳玉球, 赵德方, 等. 接头尺寸对玻璃纤维/热塑性树脂复合材料机械连接性能的影响[J]. 复合材料学报, 2019, 36(6): 1353-1363.
Chu Mingyue, Yang Yuqiu, Zhao Defang, et al.Effect of joint dimension on the mechanically fastened joint properties of glass fiber/thermoplastic resin compo-sites[J]. Acta Materiae Compositae Sinica, 2019, 36(6): 1353-1363.
[24] 梁曦东, 薛家麒. 棒形悬式合成绝缘子许用负荷的选取方法[J]. 中国电力, 1994, 27(8): 35-38.
[25] 李进, 赵仁勇, 陈允, 等. 水分含量影响玻璃纤维增强环氧树脂电树枝生长特性研究[J]. 电工技术学报, 2023, 38(5): 1166-1176, 1189.
Li Jin, Zhao Renyong, Chen Yun, et al.Effects of moisture contents on electrical treeing process in glass fiber reinforced epoxy resin[J]. Transactions of China Electrotechnical Society, 2023, 38(5): 1166-1176, 1189.
[26] Tang Jialin, Soua S, Mares C, et al.An experimental study of acoustic emission methodology for in service condition monitoring of wind turbine blades[J]. Renewable Energy, 2016, 99: 170-179.
[27] Kavaz A G, Barutcu B.Fault detection of wind turbine sensors using artificial neural networks[J]. Journal of Sensors, 2018, 2018: 5628429. |
|
|
|
2025, Vol. 40 
