Discharge Development and Characteristics of Oil-immersed Pressboard Surface with Different Moisture Contents

被引：0
|
作者：
Wu G. [1 ]
Zhou P. [1 ]
Gao B. [1 ]
Yu R. [1 ]
Hu G. [1 ]
机构：
[1] School of Electrical Engineering, Southwest Jiaotong University, Chengdu
来源：
Xinan Jiaotong Daxue Xuebao/Journal of Southwest Jiaotong University | 2020年 / 55卷 / 03期
关键词：
Discharge characteristics; Microstructure; Moisture content; Surface discharge; White mark;
D O I：
10.3969/j.issn.0258-2724.20190210
中图分类号：
学科分类号：
摘要：
The increase of moisture content in power transformer will seriously affect the insulation performance of oil-paper, more easily resulting in the surface discharge fault of insulated pressboard. In order to study the discharge characteristics of insulated pressboard with different moisture contents under AC condition, a typical model of needle board surface discharge was established. Based on the pulse current method, the characteristic charts of the surface discharge model were measured in real time, and a high-speed camera was used to record the formation and development of white mark on insulated pressboard. The variation trend of initial discharge voltage and flashover voltage under different moisture contents of pressboard was analyzed, and then that of the related discharge characteristic parameters was analyzed. The results show that the increase of moisture content in pressboard significantly reduces the onset voltage. The process of surface discharge and white mark formation and development on pressboard with different moisture contents can be divided into four stages. There is a one-to-one relationship between the four stages of surface discharge and white mark formation and development. By observing and analyzing the microstructure of insulated pressboard, it is found that the fibers of the pressboard were severely broken after tests. The higher the moisture content of the pressboard before tests, the more serious the damage to the surface of the pressboard. When the moisture content of pressboard increases from less than 0.5% to 3.8%, the initial discharge voltage decreases by 61.3%. © 2020, Editorial Department of Journal of Southwest Jiaotong University. All right reserved.
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页码：552 / 560
页数：8
相关论文
共 23 条
  • [1] YI X, WANG Z D., Surface tracking on pressboard in natural and synthetic transformer liquids under ac stress, IEEE Transactions on Dielectrics and Electrical Insulation, 20, 5, pp. 1625-1634, (2013)
  • [2] PAN Zhen, NIU Wei, Study on new characteristic quantities of spectral analysis of transformer oil paper insulation aging, Electrical Technology, 9, pp. 16-23, (2014)
  • [3] GUO Hongying, Diagnostic method of transformer insulation aging based on wavelet packet transform of polarization spectrum of voltage response, Protection and control of power system, 44, 24, pp. 170-175, (2016)
  • [4] WU Guangning, XIA Guoqiang, SONG Zhenjie, Et al., Status assessment of aging condition of transformer oil-paper insulation based on time domain dielectric spectroscopy and wavelet analysis, High Voltage Engineering, 44, 1, pp. 226-233, (2018)
  • [5] DAI J, WANG Z D, JARMAN P., Creepage discharge on insulation barriers in aged power transformers, IEEE Transactions on Dielectrics and Electrical Insulation, 17, 4, pp. 1327-1335, (2010)
  • [6] LUNDGAARD L, LINHJELL D, BERG G, Et al., Propagation of positive and negative streamers in oil with and without pressboard interfaces, IEEE Transactions on Dielectrics and Electrical Insulation, 5, 3, pp. 388-395, (1998)
  • [7] NAKAO Y, NARUSE M, SUZUKI Y, Et al., Influence of insulating barrier on the creepage discharge in transformer oil, IEEE Transactions on Dielectrics and Electrical Insulation, 4, 6, pp. 775-779, (1997)
  • [8] GAO Minhua, WU Zhirong, FU Xinian, Et al., Effect of water content on insulation performance of converter transformer, Transformer, 51, 10, pp. 21-25, (2014)
  • [9] (2014)
  • [10] LI Qun, ZHAO Yumin, JIN Yuan, Et al., Study on discharge characteristics of air gap defects in oil-paper insulation based on moisture content, Transformer, 55, 12, pp. 58-62, (2018)
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