Ageing Characteristic Quantities of Oil-Paper Insulation for Transformers Based on Extended Debye Model
Gao Jun1, Liao Ruijin1, Wang Youyuan1, Yang Lijun1, Hao Jian2, Liu Rui3, Xiao Zhongnan4
1. State Key Laboratory of Power Transmission Equipment & System Security and New Technology Chongqing University Chongqing 400044 China; 2. Chongqing Electric Power Corporation Electric Power Research Institute Chongqing 401123 China; 3. China Electric Power Research Institute Beijing 100192 China; 4. Chongqing Electric Power Corporation Overhaul Branch Company Chongqing 401123 China
Abstract：In order to extract new characteristic parameters to realize the non-destructive diagnosis of aging state of transformer oil-paper insulation by time domain dielectric response technology, the influence of the aging degree on time-domain dielectric property of oil-paper insulation is investigated. The extended Debye model for oil-paper insulation is further introduced to analyze the influences of thermal degree aging on its parameters. Then four groups of characteristic parameters are extracted to reflect the aging state of the oil-paper insulation. The quantitative relationship between the characteristic parameters and the aging state thus has been established. The test results show that the parameters of the extended Debye model are quite sensitive to the aging state. The parameters of the smallest and the largest time constant branches are both able to characterize the aging state of the insulating pressboards. An obvious exponential rule can be observed between parameters Rmin, Cmax and the degree of polymerization(DP) of the insulation paper, while the parameters Rmax, Cmin exhibit an evident linear rules with DP. The extracted characteristic parameters in this paper can be used for the aging assessment of the oil-paper insulation.
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2016, Vol. 31 
