1. Key Laboratory of Engineering Dielectrics and Its Application (Ministry of Education) Harbin University of Science and Technology Harbin 150080 China; 2. State Key Laboratory Breeding Base of Dielectrics Engineering Harbin University of Science and Technology Harbin 150080 China; 3. Heilongjiang Electric Power Research Institute Harbin 150090 China
Abstract：The moisture content in the pressboard is an important index to evaluate the aging performance of transformer insulation. In order to apply dielectric response technique to measure the moisture content of transformer pressboard, this paper deduces the equivalent model of transformer XY and the algorithm of dielectric constant of mixed dielectric. The relationship between the moisture content in pressboard and dielectric loss of XY equivalent model is obtained. At the same time, combining the experimental data and the basic idea of time-temperature superposition, the specific formulas of the real and imaginary parts of the complex dielectric constant of dehydrated pure new oil impregnated pressboard are obtained. Then the obtained formulas are introduced into the relational equation of the moisture content and dielectric loss of pressboard. A cyclic iterative fitting algorithm is obtained. XY equivalent models of three different proportions are prepared under laboratory conditions for the test of dielectric loss under different temperature conditions. Compared with the test results by the insulation pressboard moisture content test software of IDAX-300 equipment, it is found that the mean error of the moisture content calculated by the proposed iterative algorithm is 4.83%.
[1] 刘媛, 董明, 任明, 等. 油纸绝缘介电谱仿真模拟中XY模型与有限元模型对比研究[J]. 高电压技术, 2014, 40(11): 3483-3490. Liu Yuan, Dong Ming, Ren Ming, et al.Contrastive study of XY model and finite element model in dielectric spectrum simulation of oil-paper insula- tion[J]. High Voltage Engineering, 2014, 40(11): 3483-3490. [2] 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 spectro- scopy of acceleratedly thermal aging[J]. Transactions of China Electrotechnical Society, 2012, 27(5): 56-62. [3] Pahlavanpour P, Eklund M A Martins. Insulating paper ageing an furferal formation[C]//Proceedings of 2003 Electrical Insulation and Electrical Manufa- cturing & Coil Winding Technology Conference, Indianapoils, India: IEEE, 2003: 283-288. [4] Koch M, Krueger M, Tenbohlen S.On-site methods for reliable moisture determination in power trans- formers[C]//Transmission and Disribution Conference and Exposition, New Orleans, USA: IEEE, 2010: 1-6. [5] 严家明, 廖瑞金, 杨丽君, 等. 局部放电作用下油浸绝缘纸的微观结构及电气性能[J]. 中国电机工程学报, 2011, 31(19): 114-121. Yan Jiaming, Liao Ruijin, Yang Lijun, et al.Microstructure and electrical performance of oil- immersed insulation paper under patial discharge[J]. Proceedings of the CSEE, 2011, 31(19): 114-121. [6] Koch M.Improved determination of moisture in oil-paper-insulations by specialized moisture equili- brium charts[C]//Proceedings of the XIVth Inter- national Symposium on High Voltage Engineering, Beijing, 2005: 508. [7] Farahani M, Borsi H, Gockenbach E.Dielectric response studies on insulating system of high voltage rotating machines[J]. IEEE Transactions on Diele- ctrics and Electrical Insulation, 2006, 13(1): 383-393. [8] Saha T K, Purkait P.Investigation of an expert system for the condition assessment of transformer insulation based on dielectric response measure- ments[J]. IEEE Transactions on Power Delivery, 2004, 19(3): 1127-1134. [9] 廖瑞金, 袁泉, 唐超, 等. 不同老化因素对油纸绝缘介质频域谱特性的影响[J]. 高电压技术, 2010, 36(7): 1612-1618. Liao Ruijin, Yuan Quan, Tang Chao, et al.Infuence of different aging conditions on characteristics of frequency domain spectroscopy of oil-paper insu- lation medium[J]. High Voltage Engineering, 2010, 36(7): 1612-1618. [10] Sonerud B, Bengtsson T, Blennow J, et al.Dielectric response measurements utilizing semi-square voltage waveforms[J]. IEEE Transactions on Dielectrics and Electrical Insulation, 2008, 15(4): 920-926. [11] 王东阳, 周利军, 朱少波, 等. 不同温度油隙频域介电谱的归算方法[J]. 中国电机工程学报, 2016, 36(23): 6583-6592. Wang Dongyang, Zhou Lijun, Zhu Shaobo, et al.Calculation method of dielectric spectrum in frequency domain of oil gap at different temperatures[J]. Proceedings of the CSEE, 2016, 36(23): 6583-6592. [12] 廖瑞金, 刘捷丰, 吕彦东, 等. 变压器油纸绝缘含水量定量评估的频域介电特征参量研究[J]. 电工技术学报, 2015, 30(1): 204-211. Liao Ruijin, Liu Jiefeng, Lü Yandong, et al.Study on frequency domain dielectric characteristic parameters for quantitative evaluation of moisture content in transformer oil paper insulation[J]. Transactions of China Electrotechnical Society, 2015, 30(1): 204-211. [13] 廖瑞金, 郝建, 杨丽君, 等. 变压器油纸绝缘频域介电谱特性的仿真与实验研究[J]. 中国电机工程学报, 2010, 30(22): 113-119. Liao Ruijin, Hao Jian, Yang Lijun, et al.Simulation and experimental study on frequency-domain diele- ctric spectroscopy of oil-paper insulation for transformers[J]. Proceedings of the CSEE, 2010, 30(22): 113-119. [14] Gubanski S, Boss P, Csepes G, et al.Dielectric response methods for diagnostics of power trans- formers[J]. IEEE Electrical Insulation Magazine, 2003, 19(3): 12-18. [15] Paraskevas C, Vassiliou P, Dervos C.Temperature dependent dielectric spectroscopy in frequency domain of high-voltage transformer oils compared to physicochemical results[J]. IEEE Transactions on Dielectrics and Electrical Insulation, 2006, 13(3): 539-546. [16] Saha T K, Purkait P.Understanding the impacts of moisture and thermal ageing on transformer’s insulation by dielectric response and molecular weght measurements[J]. IEEE Transactions on Dielectrics and Electrical Insulation, 2008, 15(2): 568-582. [17] 王世强, 魏建林, 张冠军, 等. 温度对油纸绝缘介电响应特性的影响[J]. 电工技术学报, 2012, 27(5): 50-55. Wang Shiqiang, Wei Jianlin, Zhang Guanjun, et al.Effect of temperature on dielectric response characteristics of oil impregnated pressboard[J]. Transactions of China Electrotechnical Society, 2012, 27(5): 50-55. [18] Wang Shiqiang, Zhang Guanjun, Wei Jianlin, et al.Investigation of dielectric response characteristics of thermal aged insulating pressboard in vacuum and oil-impregnated ambient[J]. IEEE Transactions on Magnetics, 2010, 17(6): 1853-1862. [19] Liao Ruijin, Liu Jiefeng, Yang Lijun, et al.Quantitative analysis of insulation condition of oil- paper insulation based on frequency domain spectro- scopy[J]. IEEE Transactions on Dielectrics and Electrical Insulation, 2010, 22(1): 322-334. [20] 杨丽君, 齐超亮, 邓帮飞, 等. 采用修正Cole-Cole模型提取油纸绝缘频域介电谱的特征参量方法[J]. 高电压技术, 2013, 39(2): 310-317. Yang Lijun, Qi Chaoliang, Deng Bangfei, et al.Application of modified Cole-Cole model to extract characteristics of frequency dielectric spectroscopy of oil-paper insulation[J]. High Voltage Engineering, 2013, 39(2): 310-317. [21] Zaengl W S.Applications of dielectric spectroscopy in time and frequency domain for HV power equipment[J]. IEEE Electrical Insulation Magazine, 2003, 19(6): 9-22. [22] 马志钦. 变压器油纸绝缘的频域介电响应特性与绝缘状态评估方法研究[D]. 重庆: 重庆大学, 2012. [23] Aradhana R, Sridhar S, Papneja G S, et al.Moisture and dielectric properties analysis of power trans- former by DIRANA measurement[J]. Water and Energy International, 2010, 67(1): 333-344. [24] Lamkaouehi K, Ellison W J, Moreau J M.Water: a dielectric reference[J]. Journal of Molecular Liquids, 1996, 68(2): 171-279. [25] Blennow J, Ekanayake C, Walczak K, et al.Field experiences with measurements of dielectric response in frequency domain for power transformer diagno- stics[J]. IEEE Transactions on Power Delivery, 2006, 21(2): 681-688.
2018, Vol. 33 
