Abstract：In the process of manufacturing, transportation and laying, cross linked polyethylene (XLPE) cables often lead to some minor defects in the insulation layer, which may develop into electrical treeing fault. Therefore, it is necessary to carry out research on electrical treeing aging assessment and diagnosis methods in cable insulation. Dielectric response method is the most widely used non-invasive diagnostic method in recent years. When the traditional frequency domain spectroscopy (FDS) method is used to test the insulation of XLPE cables with 10 kV and above voltage levels, there are problems such as poor anti-interference ability and difficulty in measuring micro current. Therefore, based on the traditional FDS test method, I/V conversion principle and non-phase shifting transimpedance amplifier circuit, a set of low frequency high voltage FDS test system is designed in this paper. Compared with the traditional test method, the test system increases the test voltage to 7.5 kV, and adds a zero phase-shift digital filter based on FRR (forward filter, reverse filter and reverse output) algorithm, which has higher signal-to-noise ratio, better sampling accuracy and stronger anti-interference capability. In this paper, cable samples with different electrical tree aging degrees were cultivated in the laboratory, and FDS tests were carried out using the test system. For cables with the same aging degree, with the increase of test excitation voltage, the nonlinear characteristics of cables in the frequency range of 10 mHz~1 Hz become more obvious. The nonlinear characteristic parameters are quantized, and the exponential relationship between the nonlinear characteristic parameters and the electrical tree length is established. The results show that the nonlinear characteristic parameters increase exponentially with the increase of electrical tree length. The exponential function can be used to predict the length of electrical tree in a non-destructive way, so as to effectively evaluate the insulation conditions of cables. In this paper, COMSOL finite element simulation is applied to simulate and analyze the hysteresis phase of electrical tree under the applied electric field. The research in this paper also found that the electrical branches in the hysteresis stage began to become dense, and the electric fields at the tip of the branches close to each other shielded each other, which weakened the electric field strength in the insulation, reduced the degree of electric field distortion in the insulation layer, and the change of nonlinear characteristic parameters was small. The change in the width of the electrical branches had little impact on the nonlinearity represented by the cable insulation. The research method based on low frequency and high voltage frequency domain spectroscopy in this paper has certain theoretical significance for the actual XLPE cable electrical tree aging state assessment.
刘骥, 闫爽, 王守明, 张明泽, 李爽. 基于低频高压频域介电谱的XLPE电缆电树枝老化状态评估[J]. 电工技术学报, 2023, 38(9): 2510-2518.
Liu Ji, Yan Shuang, Wang Shouming, Zhang Mingze, Li Shuang. Evaluation of Electrical Tree Aging State of XLPE Cables Based on Low Frequency and High Voltage Frequency Domain Spectroscopy. Transactions of China Electrotechnical Society, 2023, 38(9): 2510-2518.
[1] 彭苏蔓, 祝曦, 吴建东, 等. 温度和电场对XLPE与纳米MgO/XLPE电树枝生长过程中局部放电特性的影响[J]. 中国电机工程学报, 2020, 40(12): 4033-4043. Peng Suman, Zhu Xi, Wu Jiandong, et al.Effect of temperature and electric field on partial discharge characteristics in XLPE and nano-MgO/XLPE during electrical tree growth[J]. Proceedings of the CSEE, 2020, 40(12): 4033-4043. [2] 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 Electrotechnical Society, 2019, 34(1): 179-191. [3] 单秉亮, 李舒宁, 杨霄, 等. XLPE配电电缆缺陷诊断与定位技术面临的关键问题[J]. 电工技术学报, 2021, 36(22): 4809-4819. Shan Bingliang, Li Shuning, Yang Xiao, et al.Key problems faced by defect diagnosis and location technologies for XLPE distribution cables[J]. Transactions of China Electrotechnical Society, 2021, 36(22): 4809-4819. [4] 周利军, 仇祺沛, 成睿, 等. 不同温度下局部气压对XLPE电缆电树枝生长及局放特性的影响[J]. 中国电机工程学报, 2016, 36(18): 5094-5102, 5135. Zhou Lijun, Qiu Qipei, Cheng Rui, et al.Influence of partial air pressure on propagation and partial discharge characteristics of electrical trees in XLPE cable under different temperatures[J]. Proceedings of the CSEE, 2016, 36(18): 5094-5102, 5135. [5] 李春阳, 韩宝忠, 张城城, 等. 电压稳定剂提高PE/XLPE绝缘耐电性能研究综述[J]. 中国电机工程学报, 2017, 37(16): 4850-4864, 4911. Li Chunyang, Han Baozhong, Zhang Chengcheng, et al.Review of voltage stabilizer improving the electrical strength of PE/XLPE[J]. Proceedings of the CSEE, 2017, 37(16): 4850-4864, 4911. [6] 刘云鹏, 刘贺晨, 李演达, 等. 直流叠加交流电压下交联聚乙烯中电树枝特性研究[J]. 电工技术学报, 2018, 33(3): 601-608. Liu Yunpeng, Liu Hechen, Li Yanda, et al.Research of the electrical tree properties in XLPE under DC-AC composite voltages[J]. Transactions of China Electrotechnical Society, 2018, 33(3): 601-608. [7] Qi Hui, Zhang Xinjun, Wang Rushan, et al.Analysis of direct current integrated charge in cable insulation with electrical tree[C]//2021 IEEE International Conference on the Properties and Applications of Dielectric Materials, Johor Bahru, Malaysia, 2021: 426-429. [8] Ohki Y, Hirai N.Detection of abnormality occurring over the whole cable length by frequency domain reflectometry[J]. IEEE Transactions on Dielectrics and Electrical Insulation, 2018, 25(6): 2467-2469. [9] 谢声益, 杨帆, 黄鑫, 等. 基于太赫兹时域光谱技术的交联聚乙烯电缆绝缘层气隙检测分析[J]. 电工技术学报, 2020, 35(12): 2698-2707. Xie Shengyi, Yang Fan, Huang Xin, et al.Air gap detection and analysis of XLPE cable insulation based on terahertz time domain spectroscopy[J]. Transactions of China Electrotechnical Society, 2020, 35(12): 2698-2707. [10] 林思衍, 周凯, 尹游, 等. 基于连续PDC测试的XLPE电缆水树老化判别方法[J]. 中国电机工程学报, 2020, 40(20): 6764-6773. Lin Siyan, Zhou Kai, Yin You, et al.Diagnosing method for water tree aging on XLPE cable based on continuous PDC test method[J]. Proceedings of the CSEE, 2020, 40(20): 6764-6773. [11] 赵艾萱, 陈曦, 徐龙, 等. 时域/频域介电响应在XLPE电缆绝缘诊断的应用[J]. 高电压技术, 2020, 46(1): 292-302. Zhao Aixuan, Chen Xi, Xu Long, et al.Application of dielectric response in diagnoses of time and frequency domain on XLPE cable insulation[J]. High Voltage Engineering, 2020, 46(1): 292-302. [12] 范贤浩, 刘捷丰, 张镱议, 等. 融合频域介电谱及支持向量机的变压器油浸纸绝缘老化状态评估[J]. 电工技术学报, 2021, 36(10): 2161-2168. Fan Xianhao, Liu Jiefeng, Zhang Yiyi, et al.Aging evaluation of transformer oil-immersed insulation combining frequency domain spectroscopy and support vector machine[J]. Transactions of China Electrotechnical Society, 2021, 36(10): 2161-2168. [13] Lafaia I, Mahseredjian J, Ametani A, et al.Frequency and time domain responses of cross-bonded cables[J]. IEEE Transactions on Power Delivery, 2018, 33(2): 640-648. [14] Guo Lei, Che Yuxuan, He Binbin, et al.Research on aging detection of vehicle EPDM cables based on frequency domain dielectric properties[C]//2020 5th Asia Conference on Power and Electrical Engineering (ACPEE), Chengdu, China, 2020: 1767-1771. [15] 吴广宁, 夏国强, 粟茂, 等. 基于频域介电谱和补偿因子的油纸绝缘水分含量和老化程度评估方法[J]. 高电压技术, 2019, 45(3): 691-700. Wu Guangning, Xia Guoqiang, Su Mao, et al.Evaluation method for moisture content and aging degree of transformer oil-paper insulation based on frequency dielectric spectroscopy and compensation factor[J]. High Voltage Engineering, 2019, 45(3): 691-700. [16] 汪先进, 周凯, 赵世林, 等. 基于冲击介电响应法的电力电缆绝缘状态评估[J]. 绝缘材料, 2020, 53(4): 59-63. Wang Xianjin, Zhou Kai, Zhao Shilin, et al.Insulation state assessment of power cables based on impulse dielectric response method[J]. Insulating Materials, 2020, 53(4): 59-63. [17] 刘亚静, 段超. 全数字自适应滤波器不同离散结构的性能对比分析[J]. 电工技术学报, 2021, 36(20): 4339-4349. Liu Yajing, Duan Chao.Performance comparison and analysis of all-digital adaptive filter with different discrete methods[J]. Transactions of China Electrote-chnical Society, 2021, 36(20): 4339-4349. [18] 陶文彪, 朱光亚, 宋述勇, 等. 交联聚乙烯中丛状电树枝的生长机制[J]. 中国电机工程学报, 2018, 38(13): 4004-4012, 4042. Tao Wenbiao, Zhu Guangya, Song Shuyong, et al.The growth mechanism of brush-type electrical tree in XLPE[J]. Proceedings of the CSEE, 2018, 38(13): 4004-4012, 4042. [19] 陈诗佳, 周凯, 李泽瑞, 等. 工频叠加冲击电压下XLPE绝缘中电树枝的生长特性研究[J]. 绝缘材料, 2020, 53(9): 42-47. Chen Shijia, Zhou Kai, Li Zerui, et al.Growth characteristics of electrical tree in XLPE insulation under power frequency voltage superimposed impulse voltage[J]. Insulating Materials, 2020, 53(9): 42-47. [20] 欧阳本红, 刘松华, 邓显波, 等. 高压XLPE电缆绝缘厚度优化设计[J]. 高电压技术, 2016, 42(8): 2388-2393. Ouyang Benhong, Liu Songhua, Deng Xianbo, et al.Optimization design for insulation thickness of high-voltage XLPE cable[J]. High Voltage Engineering, 2016, 42(8): 2388-2393.
2023, Vol. 38 
