Abstract
This paper describes the research on the electrical ageing mechanism of the resin-rich molding (RRM) insulation by the dielectric response method for large generator. The dielectric properties of the RRM insulation materials with different ageing time were measured and analysed by dielectric temperature spectrum, frequency-domain spectrum (FDS) and thermally stimulated depolarization current (TSDC). The microscopic properties of the main insulation material were also analysed by scanning electron microscope and dynamic mechanical analysis. The results of the FDS measurements showed that the dielectric loss factor \(\tan \delta\) and the real part ε of the complex dielectric constant of the main insulation material increased significantly in the frequency range of 10−2–10 Hz as the ageing time increased; the fitting results of the double relaxation HN (Havriliak–Negami) model indicated that DC conductivity and interfacial polarization increased by the electric ageing effect in the main insulation. When the test temperature exceeded the glass transition temperature, the relaxation process of turning-direction polarization changed in the main insulation system; the TSDC tests indicated that the energy levels of the deep and shallow traps were slightly reduced during the main insulation's ageing, but the number of traps increased; therefore, the ability of capturing and releasing charges was enhanced in the main insulation.
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References
Qing F, Zhiduo S, Qingguo C (2018) Dielectric response research status on ageing characteristics of large electric machinery stator bar main insulation. Large Electric Mach Hydraul Turbine 01:10–14 (in Chinese)
David E, Lamarre L (2007) Low-frequency dielectric response of epoxy–mica insulated generator bars during multi-stress ageing. IEEE Trans Dielectr Electr Insul 14(1):212–226
David E, Godin T, Bellemare J, Lamarre L (2007) Modeling of the dielectric response of a statorfrom a DC ramp test. IEEE Trans Dielectr Electr Insul 14(6):1548–1558
Fernando M, Naranpanawa W, Rathnayake R, Jayantha GA (2013) Condition assessment of statorinsulation during drying. Wetting and electrical ageing. IEEE Trans Dielectr Electr Insul 20(6):2081–2090
Ji L, Xiujing L, Xinlao W (2014) The dielectric response characteristics of curing process in Epoxy–Mica composite insulation. Electric Mach Control 018(006):22–28 (in Chinese)
Ji L (2014) Investigation of time–frequency hybrid insulation diagnosis method based on PDC analysis. Ph.D. Thesis, Harbin University of Science and Technology, Harbin, China in Chinese
Qingguo C, Zhiduo S, Qiang F, Minghe C (2017) Electrical ageing characteristics of epoxy–mica insulation of generator based on FDS. Acta Mater Compos Sin 34(9):1926–1933 (in Chinese)
Qiang F, Fanrong K, Qingguo C (2014) Ageing characteristics of tong-ma epoxy glass fiber power mica insulation materials under salt spray and humidity thermal condition. Acta Mater Compos Sin 31(3):851–858 (in Chinese)
Stone GC, Boulter EA, Culbert I, Dhirani H (2004) Electrical insulation for rotating machines: design, evaluation, ageing, testing, and repair. Wiley-IEEE Press, Hoboken
Draaper RE, Moore BJ, Rehder RH (1995) Insulation system evaluation for rotating machinery. IEEE Electr Insul Mag 11(4):19–25
Wichmann A (1983) Two decades of experience and progress in epoxy mica insulation systems for large rotating machines. IEEE Trans Power Appar Syst 102(1):74–82
Jiancheng S (1999) Study on multi-stress ageing characteristic parameters for large generator stator winding insulation. Ph.D. Thesis, Xi’An Jiaotong University, Xi’An, China in Chinese
Weifang J (1997) Dielectric physics. Machine Press, Beijing (in Chinese)
Xiaoqin M, Weisheng L, Bo L, Henkun X (2003) Study on temperature spectrum of dielectric dissipation during multi-stress ageing of large generator stator insulation. Adv Technol Electr Eng Energy 22(1):48–51 (in Chinese)
Shengjun L, Yin H, Dongri X, Daomin M, Weiwang W, Liuqing Y, Shengtao L (2016) Molecular relaxation and glass transition properties of epoxy resin at high temperature. Acta Phys Sin 65(7):1–7 (in Chinese)
Yanpeng H, Hengkun X (2008) Degradation behavior of epoxy in stator insulation of large generators in service for 23 years based on infrared spectrometric analysis. Trans China Electrotech Soc 23(3):19–23 (in Chinese)
Ming D, Yuan L, Ming R, Xuezhou W, Huanchao C, Jinzhong L (2015) Explanation study of frequency-domain dielectric spectroscopy for oil-paper insulation system. Proc Chin Soc Electr Eng 35(04):1002–1008 (in Chinese)
Bo G, Changjin H, Shuaibin L, Xiaobing Y, Xiaofeng Y, Guangning W (2017) Frequency-domain dielectric spectroscopy characteristics of generator epoxy/mica insulation. J Southwest Jiaotong Univ 052(001):9–15 (in Chinese)
Liheng W (1986) The thermally stimulated theory and applications of dielectrics. Science Press, Beijing (in Chinese)
Yuliang T (2011) Study on the ageing characteristics of composite insulator based on TSC. North China Electric Power University, Beijing (in Chinese)
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This project was supported by the State Key Laboratory of Hydropower Equipment (Grant No. 820-03-1104).
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Fu, Q., Song, Y., Chen, Q. et al. Dielectric response of resin-rich insulation ageing characteristic for large generator. Electr Eng 103, 2497–2506 (2021). https://doi.org/10.1007/s00202-021-01240-6
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DOI: https://doi.org/10.1007/s00202-021-01240-6