Effect of Degassing Treatments on Insulation Characteristics of High Voltage DC Cables
Luo Bing1, Meng Fanbo2, Wang Tingting1, Jia Lei1, Chen Xiangrong2
1. State Key Laboratory of HVDC Electric Power Research Institute China Southern Power Grid Guangzhou 510663 China; 2. Zhejiang Provincial Key Laboratory of Electrical Machine Systems College of Electrical Engineering Zhejiang University Hangzhou 310027 China
Abstract:In order to study the effect of different degassing time on the insulation properties of high-voltage DC cables, in this paper, ultra-pure cross-linked polyethylene (XLPE) cable material is used to prepare samples by flat-plate hot pressing. Four samples with different degassing time of 0h, 12h, 36h and 90h were obtained by degassing treatment at 70℃ and normal pressure. Through the current density, space charge, DC breakdown, and XRD test, the change rule of the insulation characteristics of the XLPE sample before and after degassing was studied. The results show that the space charge distribution is significantly improved after 12h of degassing, and there is almost no space charge accumulation near the electrode; The experiment after 36h of degassing has the best electrical performance, the current density is significantly reduced, and the breakdown field strength is increased by about 18kV/mm; After degassing for 90h, the crystallinity characteristic of the sample changed significantly, the crystallinity is decreased by about 11%, and the crystal diffraction peak intensity is decreased by about 62%. The above results indicate that the degassing treatment contributes to the volatilization of cross-linking by-products in the XLPE sample and the improvement of its insulating properties, and the insulation performance of the material can be improved by optimizing the degassing time, thereby reducing the production and time costs of the enterprises.
罗兵, 孟繁博, 王婷婷, 贾磊, 陈向荣. 脱气处理对高压直流电缆绝缘特性的影响[J]. 电工技术学报, 2021, 36(zk2): 730-735.
Luo Bing, Meng Fanbo, Wang Tingting, Jia Lei, Chen Xiangrong. Effect of Degassing Treatments on Insulation Characteristics of High Voltage DC Cables. Transactions of China Electrotechnical Society, 2021, 36(zk2): 730-735.
[1] 李国倡, 王家兴, 魏艳慧, 等. 高压直流电缆附件XLPE/SIR材料特性及界面电荷积聚对电场分布的影响[J]. 电工技术学报, 2021, 36(14): 3081-3089. Li Guochang, Wang Jiaxing, Wei Yanhui, et al.Effect of material properties of XLPE/SIR and interface charge accumulation on electric field distribution of HVDC cable accessory[J]. Transa-ctions of China Electrotechnical Society, 2021, 36(14): 3081-3089. [2] 李蓉, 周凯, 万航, 等. 基于输入阻抗谱的电力电缆本体局部缺陷类型识别及定位[J]. 电工技术学报, 2021, 36(8): 1743-1751. Li Rong, Zhou Kai, Wan Hang, et al.Identification and location of local defects in power cable body based on input impedance spectroscopy[J]. Transa-ctions of China Electrotechnical Society, 2021, 36(8): 1743-1751. [3] 朱煜峰, 许永鹏, 陈孝信, 等. 基于卷积神经网络的直流XLPE电缆局部放电模式识别技术[J]. 电工技术学报, 2020, 35(3): 659-668. Zhu Yufeng, Xu Yongpeng, Chen Xiaoxin, et al.Pattern recognition of partial discharges in DC XLPE cables based on convolutional neural network[J]. Transactions of China Electrotechnical Society, 2020, 35(3): 659-668. [4] 尹游, 周凯, 李诗雨, 等. 基于极化去极化电流法的水树老化XLPE电缆界面极化特性分析[J]. 电工技术学报, 2020, 35(12): 2643-2651. Yin You, Zhou Kai, Li Shiyu, et al.Interface polarization characteristics of water tree aged XLPE cables based on polarization and depolarization current method[J]. Transactions of China Electro-technical Society, 2020, 35(12): 2643-2651. [5] 潘文林, 任海洋, 梅文杰, 等. 525kV挤包绝缘柔性直流海缆脱气时间研究[J]. 绝缘材料, 2018, 51(12): 47-52. Pan Wenlin, Ren Haiyang, Mei Wenjie, et al.Study on degassing time of 525kV flexible DC submarine cable with extruded insulation[J]. Insulating Materi-als, 2018, 51(12): 47-52. [6] Tantipattarakul S, Vaughan A S, Andritsch T.On the influence of morphology and chemical defects on charge transport dynamics in polyethylene: thermal ageing and concentration gradient[J]. Journal of Physics D: Applied Physics, 2019, 52(39): 395302. [7] Bergelin P, Jeroense M, Quist T, et al.640kV extruded HVDC cable system[R/OL]. [2017-04-06].https://www.nkt.com/products-solutions/high-voltage-cable-solutions/innovation/640-kv-extruded-hvdc-cable-systems. [8] 张振鹏, 胡列翔, 赵健康, 等. 500kV海缆工厂接头绝缘恢复过渡区形成过程及电树枝特性[J]. 高电压技术, 2019, 45(11): 3413-3420. Zhang Zhenpeng, Hu Liexiang, Zhao Jiankang, et al.Formation process and electrical tree characteristics of insulation recovery transition zone of factory joints in 500kV submarine cable[J]. High Voltage Engineering, 2019, 45(11): 3413-3420. [9] Chen Xiangrong, Dai Chao, Yu Linwei, et al.Effect of thermal ageing on charge dynamics and material properties of 320kV HVDC XLPE[J]. IEEE Transa-ctions on Dielectrics and Electrical Insulation, 2019, 26(6): 1797-1804. [10] Liu Zhiquian, Hao Jian, Liao Ruijin, et al.Morphological, structural, and dielectric properties of thermally aged AC 500kV XLPE submarine cable insulation material and its deterioration condition assessment[J]. IEEE Access, 2019(7): 5065-5075. [11] 杨丽君, 李仲轩, 姚人允, 等. 获取XLPE绝缘直流电压耐受指数的步进应力试验参数选取方法研究[J]. 电工技术学报, 2019, 34(24): 5244-5251. Yang Lijun, Li Zhongxuan, Yao Renyun, et al.Selection of step-stress test parameters for obtaining DC voltage endurance coefficient of XLPE insu-lation[J]. Transactions of China Electrotechnical Society, 2019, 34(24): 5244-5251. [12] 杜伯学, 韩晨磊, 李进, 等. 高压直流电缆聚乙烯绝缘材料研究现状[J]. 电工技术学报, 2019, 34(1): 179-191. Du Boxue, Han Chenlei, Li Jin, et al.Research status of polyethylene insulation for high voltage direct current cables[J]. Transactions of China Electro-technical Society, 2019, 34(1): 179-191. [13] 苏鹏飞, 吴建东, 祝曦, 等. 脱气处理对直流电缆绝缘击穿场强的影响[J]. 中国电机工程学报, 2020, 40(2): 663-671. Su Pengfei, Wu Jiandong, Zhu Xi, et al.The influence of degassing treatment on breakdown strength in direct current cable insulation[J]. Pro-ceedings of the CSEE, 2020, 40(2): 663-671. [14] 黄光磊, 李喆, 杨丰源, 等. 直流交联聚乙烯电缆泄漏电流试验特性研究[J]. 电工技术学报, 2019, 34(1): 192-201. Huang Guanglei, Li Zhe, Yang Fengyuan, et al.Experimental research on leakage current of DC cross linked polyethylene cable[J]. Transactions of China Electrotechnical Society, 2019, 34(1): 192-201.