Aging and Moisture Evaluation Characteristic Parameters for Oil-Paper Insulation of Transformer Using Frequency Dielectric Spectroscopy
Wang Youyuan1, Gao Jun1, Liu Jiefeng1, Zhang Yiyi1, Hao Jian2, Ma Zhiqin3
1. State Key Laboratory of Power Transmission Equipment & System Security and New Technology Chongqing University Chongqing 400044 China;
2. Chongqing Electric Power Research Institute Chongqing 401123 China;
3. Guangdong Electric Power Research Institute Guangzhou 510080 China
In order to distinguish the influences of the two factors (moisture content and aging state) on the frequency domain dielectric response of oil-paper insulation samples and better apply frequency domain spectroscopy (FDS) to assess the insulation condition of on-site power transformer, oil-paper insulation samples with different moisture contents and aging states were first prepared in the laboratory, then on the basis of further study of the influences of the two factors, a new method which can distinguish the influences of moisture content and aging state by the dielectric loss factor tanδ is proposed. Moreover, new characteristic were extracted to respectively quantify these two factors. The research results show that the characteristic parameters are sensitive to the moisture content in 10-1~10Hz, while only affected significantly by aging states in 10-3~10-1Hz. Meanwhile, the maximum values of characteristic parameters in above two frequency ranges have the obvious exponential relationship with the degree of polymerization (DP) and moisture content, respectively, which are used to assess the conditions of oil-paper insulation. The characteristic parameters extracted in this paper can be applied to realize the non-destructive condition diagnosis of oil-paper insulation of transformer.
王有元, 高竣, 刘捷丰, 张镱议, 郝建, 马志钦. 变压器油纸绝缘老化与水分含量评估频域介电特征量[J]. 电工技术学报, 2015, 30(22): 215-221.
Wang Youyuan, Gao Jun, Liu Jiefeng, Zhang Yiyi, Hao Jian, Ma Zhiqin. Aging and Moisture Evaluation Characteristic Parameters for Oil-Paper Insulation of Transformer Using Frequency Dielectric Spectroscopy. Transactions of China Electrotechnical Society, 2015, 30(22): 215-221.
[1] 廖瑞金, 梁帅伟, 杨丽君, 等. 天然酯-普通纸（或热稳定纸）绝缘热老化特性[J]. 电工技术学报, 2009, 24(12): 12-17.
Liao Ruijin, Liang Shuaiwei, Yang Lijun, et al. Insulation thermal aging properties of natural ester immersed paper comparing with that of conventional and thermally upgraded papers[J]. Transactions of China Electrotechnical Society, 2009, 24(12): 12-17.
[2] Emsley A M, Stevens G C. Review of chemical indicators of degradation of cellulosic electrical paper insulation in oil-filled transformers[J]. Proceedings of IEE Science, Measurement and Techno- logy, 1994, 141(5): 324-334.
[3] Shroff D H, Stannett A W. Review of paper ageing in power transformers[J]. IEE Proceedings of Generation, Transmission and Distribution, 1985, 132(6): 312-319.
[4] Pahlavanpour P, Eklund, Martins M A．Insulating paper ageing and furfural formation[C]. Proceedings of Electrical Insulation and Electrical Manufacturing & Coil Winding Technology Conference, Indian- apolis, United States, 2003: 283-288.
[5] Saha T K. Review of modern diagnostic techniques for assessing insulation condition in aged trans-
formers[J]. IEEE Transactions on Dielectrics and Electrical Insulation, 2003, 10(5): 903-917.
[6] Zaengl W S. Application of dielectric spectroscopy intime and frequency domain for HV power equip-
ment[J]. IEEE Electrical Insulation Magazine, 2003, 19(6): 9-22.
[7] Blennow J, Ekanayake C, Walczak K, et al. Field experiment with measurement of dielectric response in frequency domain for power transformer diagnostics[J]. IEEE Transactions on Dielectric and Electrical Insulation, 2006, 21(2): 681-688.
[8] Kuang Y C, Chen G, Jarmm P. Recovery voltage measurement on oil-paper insulation with simple geometry and controlled environment[C]. Proceedings of the IEEE International Conference on Solid Diele- ctrics, Toulouse, France, 2004, 2: 739-742.
[9] Saha T K, Purkait P. Investigation of polarization and depolarization current measurements for the assessment of oil-paper insulation of aged transformers[J]. IEEE Transactions on Dielectrics and Electrical Insulation, 2004, 11(1): 144-154.
[10] Farahani M, Borsi H, Gockenbach E. Dielectric response studies on insulating system of high voltage rotating machines[J]. IEEE Transactions on Dielectrics and Electrical Insulation, 2006, 13(1): 383-393.
[11] Yew J H, Pradhan M K, Saha T K. Effects of moisture and temperature on the frequency domain spectroscopy analysis of power transformer insulation[C]. IEEE Power Engineering Society General Meeting, Pittsburgh, USA, 2008: 1-8.
[12] Liao R, Hao J, Chen G, et al. Quantitative analysis of ageing condition of oil-paper insulation by frequency domain spectroscopy[J]. IEEE Transactions on Dielectrics and Electrical Insulation, 2012, 19(3): 821-830.
[13] 廖瑞金, 郝建, 杨丽君, 等. 变压器油纸绝缘频域介电特征量与绝缘老化状态的关系[J]. 电工技术学报, 2012, 27(5): 43-49, 76.
Liao Ruijin, Hao Jian, Yang Lijun, et al. Relationship between frequency domain dielectric characteristic quantity and aging status of transformer oil-paper insulation[J]. Transactions of China Electrotechnical society, 2012, 27(5): 43-49, 76.
[14] Ekanayake C, Gubanski S M, Graczkowski A, et al. Frequency response of oil impregnated pressboard and paper samples for estimating moisture in transformer insulation[J]. IEEE Transactions on Power Delivery, 2006, 21(3): 1309-1317.
[15] 魏建林, 王世强, 彭华东, 等. 变压器油纸绝缘的介电响应特性研究—加速热老化的介电谱[J]. 电工技术学报, 2012, 27(5): 56-62.
Wei Jianlin, Wang Shiqiang, Peng Huadong, et al. Investigation of dielectric response characteristics of transformer oil-paper insulation—dielectric spectroscopy of acceleratedly thermal aging[J]. Transactions of China Electrotechnical Society, 2012, 27(5): 56-62.
[16] Saha T K, Purkait P. Investigations of temperature effects on the dielectric response measurements of transformer oil-paper insulation system[J]. IEEE Trans- actions on Power Delivery, 2008, 23(1): 252-260.
[17] Setayeshmehr A, Fofana I, Akbari A, et al. Effect of temperature, water content and aging on the dielectric response of oil-impregnated paper[C]. IEEE Inter-
national Conference on Dielectric Liquids, France, 2008: 1-4.
[18] Saha T K, Purkait P. Effects of temperature on time-domain dielectric diagnostics of transformers[C]. Institution of Engineers, Australia, 2004:157-162.
[19] Gielniak J, Graczkowski A, Moranda H, et al. Moisture in cellulose insulation of power transformers-
statistics[J]. IEEE Transactions on Dielectrics and Electrical Insulation, 2013, 20(3): 981-987.
[20] 杨丽君, 廖瑞金, 孙会刚, 等. 变压器油纸绝缘热老化特性及特征量研究[J]. 电工技术学报, 2009, 24(8): 27-33.
Yang Lijun, Liao Ruijin, Sun Huigang, et al. Investi-
21 gation on properties and characteristics of oil-paper insulation in transformer during thermal degradation process[J]. Transactions of China Electrotechnical Society, 2009, 24(8): 27-33.
[21] 陈季丹, 刘子玉. 电介质物理学[M]. 北京: 机械工业出版社, 1982.
[22] 郝建, 廖瑞金, 杨丽君, 等. 应用频域介电谱法的变压器油纸绝缘老化状态评估[J]. 电网技术, 2011, 35(7): 187-193.
Hao Jian, Liao Ruijin, Yang Lijun, et al. Aging status assessment of power transformer oil-paper insulation by frequency-domain dielectric spectroscopy[J]. Power System Technology, 2011, 35(7): 187-193.
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