Comparison of AC breakdown characteristics on insulation paper (pressboard) immersed by three-element mixed insulation oil and mineral oil  

作　　者：Dawei Feng Jian Hao Lijun Yang Ruijin Liao Xin Chen Jian Li 

机构地区：[1]State Key Laboratory of Power Transmission Equipment and System Security and New Technology,School of Electrical Engineering,Chongqing University,Chongqing 400044,People's Republic of China

出　　处：《High Voltage》2020年第3期298-305,共8页高电压（英文）

摘　　要：Insulation oil is an important dielectric in power devices,and many studies on mixed insulation oil have been conducted in recent years to improve the performance of insulation oils.To replace mineral oil directly,the authors previously developed a novel three-element mixed insulation oil successfully;the main parameters of which satisfy the IEC 60296-2012 standard for mineral oil.In the present study,the AC breakdown properties of insulation paper(pressboard)immersed by the new mixed oil and naphthenic mineral oil were compared.For both insulation oils,the increase in temperature cannot significantly reduce the breakdown strength of oil-immersed insulation paper(pressboard)at a low moisture content,and the increment of moisture content cannot reduce the breakdown voltage at a low temperature(25℃).The breakdown voltage decreases only when the two factors increase simultaneously.For the mixed and mineral oils,the AC breakdown voltage of oilimmersed paper(pressboard)with different thicknesses has significant difference.The mineral oil has a high breakdown voltage for the thin insulation paper,whereas the mixed oil has a high breakdown voltage when the thickness of the insulation paper(pressboard)exceeds 0.2 mm.This phenomenon is mainly caused by the breakdown field strength that varies with the increase of dielectric thickness and the different change trends of paper(pressboard)immersed with the mixed and the mineral oils.Moreover,the stack of thin multilayer insulation paper enables the mixed oil-immersed paper to have a higher breakdown strength than the mineral oil-immersed paper.For the AC breakdown voltage of oil-immersed pressboard with an oil-gap structure,the mixed oil is comprehensively superior to the mineral oil due to its larger relative permittivity.

关 键 词：INSULATION immersed BREAKDOWN 

分 类 号：TM855[电气工程—高电压与绝缘技术]