Abstract：With the development of power system, the transmission voltage level of cable is continuously improved, and electrical stress plays a more and more important role in the failure process of cross-linked polyethylene (XLPE) insulation. It is necessary to deeply study the electrical aging life of XLPE. However, the influence of electrical stress on the performance of insulating materials is distributed in a probabilistic manner. Even under the same experimental condition, the insulation failure time of the samples also has a large dispersion. To improve the accuracy of electrical life assessment of cable insulation material, this paper modifies the traditional XLPE electrical life model based on the inverse power law according to the statistical characteristics of XLPE failure time. First, the voltage endurance test was carried out on the XLPE sheet samples, and the failure time of XLPE under the action of different field strengths is counted. The XLPE sheet samples for the study was provided by a cable manufacturer with a size of 200 mm×200 mm×1 mm。According to the samples power frequency field strong breakdown test results and the standard GB/T 29311, the voltage endurance test field intensities were determined to be 36 kV/mm, 33 kV/mm, 32 kV/mm, 30 kV/mm and 28 kV/mm respectively. Secondly, according to the voltage endurance test results, the statistical characteristics of the failure time of XLPE sheet samples were analyzed. In order to reduce the impact of subjective factors on the results, density based spatial clustering of applications with noise (DBSCAN) algorithm was used to divide the samples failure time according to the distribution concentration of data points. The results show that under the same field intensity, the failure time of XLPE was roughly distributed in three time intervals. The relationship between samples failure time and electric field intensity was analyzed. Combined with the observation results of material micro morphology, it can be seen that different failure time intervals of XLPE correspond to different insulation failure processes. When the electric field intensity was different, the dominant failure process was also different. Finally, the traditional XLPE electrical life model based on the inverse power law was modified according to the statistical characteristics of the failure time of the XLPE sheet samples. The failure time of the dominant failure process samples was used to represent the electrical life of the XLPE sheet samples under the field intensity, and the modified XLPE electrical life model was obtained. Compared with the traditional electric life model, the modified model determines the position of the inflection point in the E-t characteristic curve from the perspective of the statistical characteristics of the failure time. According to the modified model, when the electric field intensity E≥32 kV/mm, the XLPE life index n1=20.73; When the electric field intensity E<32 kV/mm, the XLPE life index n2=28.45.
王国栋, 周凯, 李原, 李诗雨, 傅尧. 基于失效时间统计特性的交联聚乙烯电寿命模型修正[J]. 电工技术学报, 2023, 38(4): 1042-1050.
Wang Guodong, Zhou Kai, Li Yuan, Li Shiyu, Fu Yao. Modification of Cross-Linked Polyethylene Electrical Life Model Based on Statistical Characteristics of Failure Time. Transactions of China Electrotechnical Society, 2023, 38(4): 1042-1050.
[1] 陈向荣, 孟繁博, 夏峰, 等. 脱气处理对高压直流用500kV XLPE绝缘特性及其聚集形态的影响[J]. 中国电机工程学报, 2021, 41(10): 3645-3656, 3688. Chen Xiangrong, Meng Fanbo, Xia Feng, et al.Effect of degassing treatment on 500kV XLPE insulation characteristics and aggregation structure[J]. Pro-ceedings of the CSEE, 2021, 41(10): 3645-3656, 3688 [2] 周凯, 李诗雨, 尹游, 等. 退运中压XLPE和EPR电缆老化特性分析[J]. 电工技术学报, 2020, 35(24): 5197-5206. Zhou Kai, Li Shiyu, Yin You, et al.Analysis of aging characteristics of medium voltage XLPE and EPR retired cables[J]. Transactions of China Electro-technical Society, 2020, 35(24): 5197-5206. [3] 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. [4] 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]. Transa-ctions of China Electrotechnical Society, 2021, 36(22): 4809-4819. [5] 刘英, 陈嘉威, 赵明伟, 等. 高压XLPE电缆平滑铝复合护套的弯曲特性及结构设计[J]. 电工技术学报, 2021, 36(23): 5036-5045. Liu Ying, Chen Jiawei, Zhao Mingwei, et al.Bending characteristics and structure design of smooth aluminum composite sheath in HV XLPE cables[J]. Transactions of China Electrotechnical Society, 2021, 36(23): 5036-5045. [6] 饶显杰, 周凯, 黄永禄, 等. 频域反射法中阻抗变化类型判断技术[J]. 电工技术学报, 2021, 36(16): 3457-3466. Rao Xianjie, Zhou Kai, Huang Yonglu, et al.Type judgement technology of impedance variation in frequency domain reflection method[J]. Transactions of China Electrotechnical Society, 2021, 36(16): 3457-3466. [7] 沈智飞, 柳宝坤, 王国栋, 等. 10kV交联聚乙烯电缆加速电老化特性研究[J]. 绝缘材料, 2021, 54(8): 60-66. Shen Zhifei, Liu Baokun, Wang Guodong, et al.Accelerated electrical ageing characteristics of 10kV XLPE cable[J]. Insulating Materials, 2021, 54(8): 60-66. [8] 吴明祥, 欧阳本红, 李文杰. 交联电缆常见故障及原因分析[J]. 中国电力, 2013, 46(5): 66-70. Wu Mingxiang, Ouyang Benhong, Li Wenjie, et al.Common faults and cause analysis of XLPE cables[J]. Electric Power, 2013, 46(5): 66-70. [9] Kumar C, Mishra M K, Mekhilef S.A new voltage control strategy to improve performance of DSTATCOM in electric grid[J]. CES Transactions on Electrical Machines and Systems, 2020, 4(4): 295-302. [10] 胡一卓, 董明, 谢佳成, 等. 聚合物绝缘材料多因子老化的研究现状与发展[J]. 电网技术, 2020, 44(4): 1276-1289. Hu Yizhuo, Dong Ming, Xie Jiacheng, et al.Status and progress in multi-factor ageing research for polymer insulation materials[J]. Power System Tech-nology, 2020, 44(4): 1276-1289. [11] Tanaka T, Greenwood A. Effects of charge injection and extraction on tree initiation in polyethylene[J]. IEEE Transactions on Power Apparatus & Systems, 1978, PAS-97(5): 1749-1759. [12] Bamji S S, Bulinski A T.Degradation of polymeric insulation due to photoemission caused by high electric fields[J]. IEEE Transactions on Electrical Insulation, 1989, 24(1): 91-98. [13] 李忠华, 尹毅, 朱军, 等. 聚合物绝缘电热联合老化的陷阱理论和实验验证[J]. 中国电机工程学报, 1999, 19(2): 70-74. Li Zhonghua, Yin Yi, Zhu Jun, et al.Trap theory of combined aging under electrical and thermal stress in polymers and its test verification[J]. Transactions of China Electrotechnical Society, 1999, 19(2): 70-74. [14] 霍瑞美. 交联聚乙烯热老化监测及快速热寿命评估[D]. 上海: 上海交通大学, 2014. [15] 刘英, 姜晖, 曹晓珑. 现役交流XLPE电缆绝缘切片试样的交、直流耐压性能对比[J]. 高电压技术, 2017, 43(11): 3559-3567. Liu Ying, Jiang Hui, Cao Xiaolong.Comparison of AC and DC voltage endurance properties of insulation sheet samples spirally-cut from existing AC XLPE cables[J]. High Voltage Engineering, 2017, 43(11): 3559-3567. [16] Wang Ya, Lü Zepeng, Wang Xia, et al.Estimating the inverse power law aging exponent for the DC aging of XLPE and its nanocomposites at different tempera-tures[J]. IEEE Transactions on Dielectrics & Electrical Insulation, 2017, 23(6): 3504-3513. [17] 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. [18] 刘霞, 于钦学, 刘明昊, 等. 160kV直流XLPE电缆绝缘的直流E-t特性[J]. 高电压技术, 2019, 45(1): 130-135. Liu Xia, Yu Qinxue, Liu Minghao, et al.DC E-t characteristics of 160kV DC XLPE cable insulation[J]. High Voltage Engineering, 2019, 45(1): 130-135. [19] 龙尧. 考虑电应力的XLPE寿命评估方法及试验装置研究[D]. 重庆: 重庆理工大学, 2020. [20] 张怡. 交联聚乙烯直流电-热联合老化特性研究[D]. 北京: 华北电力大学, 2018. [21] 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): 663-672. Su Pengfei, Wu Jiandong, Zhu Xi, et al.Effect of degassing treatment on breakdown strength in direct current cable insulation[J]. Proceedings of the CSEE, 2020, 40(2): 663-672. [22] 刘刚, 刘斯亮, 金尚儿, 等. 基于理、化、电特性的110kV XLPE绝缘电缆剩余寿命的综合评估[J]. 电工技术学报, 2016, 31(12): 72-79, 107. Liu Gang, Liu Siliang, Jin Shanger, et al.Com-prehensive evaluation of remaining life of 110kV XLPE insulated cable based on physical, chemical and electrical properties[J]. Transactions of China Electrotechnical Society, 2016, 31(12): 72-79, 107. [23] 王霞, 孙晓彤, 刘全宇, 等. 基于空间电荷效应的绝缘老化寿命模型的研究进展[J]. 高电压技术, 2016, 42(3): 861-867. Wang Xia, Sun Xiaotong, Liu Quanyu, et al.Research development of aging models of insulation materials based on space charge effect[J]. High Voltage Engin-eering, 2016, 42(3): 861-867. [24] 汪颖, 谢佳妮, 邓凌峰, 等. 基于典型波形特征与改进DBSCAN的电压暂降同源识别方法[J]. 电力系统自动化, 2021, 45(11): 126-135. Wang Ying, Xie Jiani, Deng Lingfeng, et al.Identification method for same-source voltage sags based on typical waveform characteristics and improved density-based spatial clustering of appli-cations with noise[J]. Automation of Electric Power Systems, 2021, 45(11): 126-135. [25] 刘苏, 黄纯, 侯帅帅, 等. 基于DDTW距离与DBSCAN算法的户变关系识别方法[J]. 电力系统自动化, 2021, 45(18): 71-77. Liu Su, Huang Chun, Hou Shuaishuai, et al.Identification method for household-transformer relationship based on derivative dynamic time warping distance and density-based spatial clustering of application with noise algorithm[J]. Automation of Electric Power Systems, 2021, 45(18): 71-77. [26] 刘宁, 李元, 徐尧宇, 等. 役龄累积和状态诱因协同的变压器失效概率模型[J]. 中国电机工程学报, 2019, 39(22): 6783-6791. Liu Ning, Li Yuan, Xu Yaoyu, et al.A failure probability model of transformers merging increasing service years and operating state inducements[J]. Proceedings of the CSEE, 2019, 39(22): 6783-6791. [27] 薛安成, 罗麟, 景琦, 等. 基于三参数Weibull分布的继电保护装置老化失效率估算[J]. 电力系统保护与控制, 2014, 42(24): 72-78. Xue Ancheng, Luo Lin, Jing Qi, et al.Research on aging failure rate estimation of protective relay based on three-parameter Weibull distribution[J]. Power System Protection and Control, 2014, 42(24): 72-78. [28] Montanari G C, Seri P, Dissado L A.Aging mechanisms of polymeric materials under DC electrical stress: a new approach and similarities to mechanical aging[J]. IEEE Transactions on Dielectrics & Electrical Insu-lation, 2019, 26(2): 634-641.
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