%A Zhiyong LIN,Damin ZHANG,Xungao ZHONG,Jianbin ZENG,Qiang ZHANG %T Analysis of insulation state of transformer based on aging factor %0 Journal Article %D 2019 %J Journal of Shandong University(Engineering Science) %R 10.6040/j.issn.1672-3961.0.2018.330 %P 114-119 %V 49 %N 1 %U {http://gxbwk.njournal.sdu.edu.cn/CN/abstract/article_1800.shtml} %8 2019-02-01 %X

For further studying effect of extended Debye equivalent circuit on insulation medium aging of transformer, the extended Debye equivalent circuit of transformer was built using the characteristic of return voltage polarization spectrum. By analysis of equivalent circuit parameters' effect on return voltage polarization spectrum, the insulation medium aging of transformer was obtained finally. The simulation and examples analysis results showed that: polarization branch with large time constant reflected the aging of insulation paper in the transformer; polarization branch with small time constant reflected the aging of insulation oil in the transformer. Based on equivalent circuit parameters, aging factor (KL) was defined to analyze insulation state of transformer. The intrinsic relationship between the aging factor and insulation state of transformer was obtained. The analysis results demonstrated that insulation state of transformer was good when KL in range between [0, 10]; Insulation state of transformer was general when KL in range between [10, 30]; Insulation state of transformer was aged seriously when KL in range between [30, ∞].