Insulation condition diagnosis of oil-immersed paper insulation based on non-linear frequency-domain dielectric response

• Published in: IEEE transactions on dielectrics and electrical insulation Vol. 25; no. 5; pp. 1980 - 1988
• Main Authors: Zhang, Daning, Yun, Hao, Zhan, Jiangyang, Sun, Xiang, He, Wenlin, Niu, Chaobin, Mu, Haibao, Zhang, Guan-jun
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.10.2018; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Aging; aging degree; Dielectrics; Electric fields; Frequency domain analysis; frequency domain spectroscopy; Insulation; Ions; Moisture; Moisture content; non-linear dielectric response; Nonlinear phenomena; Nonlinear response; oil-immersed paper; Oils; Parameter estimation; Resistance
• ISSN: 1070-9878; 1558-4135
• DOI: 10.1109/TDEI.2018.007076

In this work, samples of oil-immersed paper with different moisture levels and aging condition were studied. Frequency domain spectroscopy (FDS) of the samples was examined at 40 °C under different excitation voltages. A non-linear phenomenon in frequency domain dielectric response with different moisture contents and aging condition was observed. The non-linear phenomenon appears to be related to the hindrance effect of cellulose on the movement of ions and the Poole-Frenkel effect on the concentration of ions. With aging, the nonlinear loss peaks at different frequencies caused by the effect of nonlinear conductance and interface polarization appear in the FDS results. The non-linear phenomenon was modeled and verified experimentally. The characteristic parameters and quantitative method to estimate moisture content and the degree of aging degree of oil-immersed paper can be obtained by the proposed method.