AC Surface Flashover and Gas Generation Difference of the Cellulose Insulation Pressboard Immersed in Novel 3-Element Mixed Oil and Mineral Oil

Surface flashover fault is one of the most challenge issues in oil-cellulose insulation pressboard system used in power transformer. In this study, a comparative study of the AC surface flashover properties of the novel 3-element mixed oil-cellulose insulation pressboard (3EMO-IP) and mineral oil-cellulose insulation pressboard (MO-IP) was performed under needle-plate and finger-finger electrode, respectively, measurement including dielectric property, surface flashover voltage, damage of cellulose pressboard surface and the gas generation behaviors after multiple surface flashover. Results show that the cellulose insulation pressboard immersed in the novel 3-element mixed insulation oil (3EMO) has higher relative permittivity and dielectric loss factor at 50 Hz, and also has slightly lower surface resistivity. The AC surface flashover voltage of the 3EMO-IP is higher than that of MO-IP under needle-plate and finger-finger electrode (electrode distance 5 mm, 10 mm, 15 mm and 20 mm). Compared to MO-IP, the lower electric field intensity at the oil-pressboard interface, as well as more difficult for surface charge accumulation of 3EMO-IP and the higher breakdown voltage of 3EMO lead to the higher AC surface flashover voltage of 3EMO-IP. Moreover, the carbonization of fibers in 3EMO-IP is slightly less. After multiple surface flashover, C2H2 and total hydrocarbon gases are the main differences between 3EMO-IP and MO-IP, which is more marked with the increase of flashover times. This study offers a reference for improving the surface flashover property of oil-pressboard insulation system by using 3EMO.

[1]  J.M. Lehr,et al.  Surface flashover of oil-immersed dielectric materials in uniform and non-uniform fields , 2009, IEEE Transactions on Dielectrics and Electrical Insulation.

[2]  Haoyong Song,et al.  Influences of moisture content on insulation properties of vegetable insulating oil , 2014, 2014 ICHVE International Conference on High Voltage Engineering and Application.

[3]  Y. Zhang,et al.  Aging condition assessment of transformer oil-immersed cellulosic insulation based upon the average activation energy method , 2019, Cellulose.

[4]  Chao Tang,et al.  Review of Research Progress on the Electrical Properties and Modification of Mineral Insulating Oils Used in Power Transformers , 2018 .

[5]  Henry B. H. Sitorus,et al.  Jatropha curcas methyl ester oil obtaining as vegetable insulating oil , 2016, IEEE Transactions on Dielectrics and Electrical Insulation.

[6]  A. Beroual,et al.  Influence of the voltage waveform and hydrostatic pressure on morphology and final length of discharges propagating over solid-liquid interfaces , 2009, IEEE Transactions on Dielectrics and Electrical Insulation.

[7]  Ruijin Liao,et al.  Influence of Amine Compounds on the Thermal Stability of Paper-Oil Insulation , 2018, Polymers.

[8]  Caixin Sun,et al.  Influence of vegetable oil on the thermal aging rate of kraft paper and its mechanism , 2010, 2010 International Conference on High Voltage Engineering and Application.

[9]  U. M. Rao,et al.  Performance analysis of alternate liquid dielectrics for power transformers , 2016, IEEE Transactions on Dielectrics and Electrical Insulation.

[10]  Markus Zahn,et al.  Surface flashover breakdown mechanisms on liquid immersed dielectrics , 2012 .

[11]  Ma Zhi-qin Simulation and Experimental Study on Frequency-domain Dielectric Spectroscopy of Oil-paper Insulation for Transformers , 2010 .

[12]  A. Beroual,et al.  Investigation on creeping discharges propagating over pressboard immersed in mineral and vegetable oils under AC, DC and lightning impulse voltages , 2013, IEEE Transactions on Dielectrics and Electrical Insulation.

[13]  K. Miyagi,et al.  Negative discharge response of blend oil (ester-based insulating oil with aging mineral oil) in a non-uniform field , 2017, 2017 IEEE 19th International Conference on Dielectric Liquids (ICDL).

[14]  M A G Martins,et al.  Vegetable oils, an alternative to mineral oil for power transformers- experimental study of paper aging in vegetable oil versus mineral oil , 2010, IEEE Electrical Insulation Magazine.

[15]  Lijun Yang,et al.  Comparison of ageing results for transformer oil-paper insulation subjected to thermal ageing in mineral oil and ageing in retardant oil , 2012, IEEE Transactions on Dielectrics and Electrical Insulation.

[16]  R. Setiabudy,et al.  Comparative study of AC and DC breakdown voltages in Jatropha methyl ester oil, mineral oil, and their mixtures , 2018, IEEE Transactions on Dielectrics and Electrical Insulation.

[17]  Fernando Delgado,et al.  Quantitative study on the aging of kraft paper in vegetable oils , 2016, IEEE Electrical Insulation Magazine.

[18]  B. X. Du,et al.  Surface functional graded spacer for compact HVDC gaseous insulated system , 2019, IEEE Transactions on Dielectrics and Electrical Insulation.

[19]  Roberto Asano,et al.  Comparative aging characteristics between a high oleic natural ester dielectric liquid and mineral oil , 2014, IEEE Transactions on Dielectrics and Electrical Insulation.

[20]  Jian Li,et al.  Thermal and electrical properties of a novel 3-element mixed insulation oil for power transformers , 2019, IEEE Transactions on Dielectrics and Electrical Insulation.

[21]  A. Denat,et al.  High field conduction and prebreakdown phenomena in dielectric liquids , 2006, IEEE Transactions on Dielectrics and Electrical Insulation.

[22]  G. B. Kumbhar,et al.  Effects of impurities on surface discharges at synthetic ester/cellulose board , 2019, IEEE Transactions on Dielectrics and Electrical Insulation.

[23]  Hanbo Zheng,et al.  A Novel Universal Approach for Temperature Correction on Frequency Domain Spectroscopy Curve of Transformer Polymer Insulation , 2019, Polymers.

[24]  Masayuki Hikita,et al.  Finite-Element Analysis for Surface Discharge Due to Interfacial Polarization at the Oil-Nanocomposite Interface , 2018, IEEE Transactions on Magnetics.

[25]  Ruijin Liao,et al.  Comparative Study on the Thermal-Aging Characteristics of Cellulose Insulation Polymer Immersed in New Three-Element Mixed Oil and Mineral Oil , 2019, Polymers.