Effects of temperature on creepage discharge characteristics in oil-impregnated pressboard insulation under combined AC–DC voltage  

作　　者：Fubao JIN Yuanxiang ZHOU Bin LIANG Zhongliu ZHOU Ling ZHANG 金福宝;周远翔;梁斌;周仲柳;张灵(Key Laboratory of Plateau Ecology and Agriculture,College of Agriculture and Animal Husbandry,School of Water Resources and Electric Power,Qinghai University,Xining 800016,People's Republic of China;State Key Lab of Control and Simulation of Power Systems and Generation Equipments,Department of Electrical Engineering,Tsinghua University,Beijing 100084,People's Republic of China)

机构地区：[1]Key Laboratory of Plateau Ecology and Agriculture,College of Agriculture and Animal Husbandry,School of Water Resources and Electric Power,Qinghai University,Xining 800016,People's Republic of China [2]State Key Lab of Control and Simulation of Power Systems and Generation Equipments,Department of Electrical Engineering,Tsinghua University,Beijing 100084,People's Republic of China

出　　处：《Plasma Science and Technology》2019年第5期14-22,共9页等离子体科学和技术（英文版）

基　　金：supported by the Natural Science Foundation of Qinghai Province(No.2016-ZJ-925Q);Chinese National Programs for Fundamental Research(No.2011CB209400)

摘　　要：Due to the complexity of the valve side winding voltage of the converter transformer, the insulation characteristics of the oil-impregnated pressboard(OIP) of the converter transformer are different from those of the traditional AC transformer. The study on effect of temperature on the creeping discharge characteristics of OIP under combined AC–DC voltage is seriously inadequate. Therefore, this paper investigates the characteristics of OIP creepage discharge under combined AC–DC voltage and discusses the influence of temperature on creepage discharge characteristics under different temperatures from 70 °C to 110 °C. The experimental results show that the partial discharge inception voltage and flashover voltage decrease with increasing temperature. The times of low amplitude discharge(LAD) decrease and amplitude of LAD increases. Simultaneously, the times of high amplitude discharge(HAD) gradually increase at each stage of creepage discharge with higher temperature. The analysis indicates that the charge carriers easily accumulate and quickly migrate directional movement along the electric field ahead of discharging. The residual charge carriers are more easily dissipated after discharging.The ‘hump’ region of LAD moves to the direction of higher discharge magnitude. The interval time between two continuous discharges is shortened obviously. The concentration of HAD accelerates the development of OIP insulation creepage discharge. The temperature had an accelerating effect on the development of discharge in the OIP under applying voltage.Due to the complexity of the valve side winding voltage of the converter transformer,the insulation characteristics of the oil-impregnated pressboard(OIP)of the converter transformer are different from those of the traditional AC transformer.The study on effect of temperature on the creeping discharge characteristics of OIP under combined AC-DC voltage is seriously inadequate.Therefore,this paper investigates the characteristics of OIP creepage discharge under combined AC-DC voltage and discusses the influence of temperature on creepage discharge characteristics under different temperatures from 70℃to 110℃.The experimental results show that the partial discharge inception voltage and flashover voltage decrease with increasing temperature.The times of low amplitude discharge(LAD)decrease and amplitude of LAD increases.Simultaneously,the times of high amplitude discharge(HAD)gradually in crease at each stage of creepage discharge with higher temperature.The analysis indicates that the charge carriers easily accumulate and quickly migrate directional movement along the electric field ahead of discharging.The residual charge carriers are more easily dissipated after discharging.The'hump'region of LAD moves to the direction of higher discharge magnitude.The interval time between two continuous discharges is shortened obviously.The concentration of HAD accelerates the development of OIP insulation creepage discharge.The temperature had an accelerating effect on the development of discharge in the OIP under applying voltage.

关 键 词：oil-impregnated PRESSBOARD INSULATION combined AC-DC VOLTAGE inception VOLTAGE CREEPAGE discharge temperature flashover VOLTAGE 

分 类 号：TL[核科学技术]