The electrical tree discharge channel will be formed at concentrate spot of electric field in solid insulation dielectric,in order to study the difference of electrical tree under different electrical field,the short-...The electrical tree discharge channel will be formed at concentrate spot of electric field in solid insulation dielectric,in order to study the difference of electrical tree under different electrical field,the short-cable electrode system with actual XLPE cable was designed,experiments were performed under 12 kV,15 kV,18 kV,21 kV compare to the needle-plate electrode system.Experiment results show that the electrical tree of short-cable electrode system have the same growth trend with the needle-plate electrode system in the growing characteristic,the dense of electrical tree increase with the increase of voltage level,electrical tree of short-cable electrode system growth is slower than the needle-plate electrode system at the same voltage;To get the same shape of electrical tree,the voltage of short-cable electrode system must be higher than needle-plate electrode system,the results show that the semiconductor layer and the copper shield layer outside of XLPE cable have very important affection on the electrical trees degradation.展开更多
文中搭建了252 k V GIS局部放电实验平台,采用内置式、外置式UHF传感器以及自主研制的利用盆式绝缘子内部均压屏蔽环的抽取式环形UHF传感器,实验研究不同传感器的频率响应特性和在高压导体金属尖端、悬浮电位、盆式绝缘子边遗留金属垫...文中搭建了252 k V GIS局部放电实验平台,采用内置式、外置式UHF传感器以及自主研制的利用盆式绝缘子内部均压屏蔽环的抽取式环形UHF传感器,实验研究不同传感器的频率响应特性和在高压导体金属尖端、悬浮电位、盆式绝缘子边遗留金属垫片和自由金属颗粒等4种典型绝缘缺陷下的检测特性,并探讨了不同电压下局放的发展规律。结果表明,内置式、外置式和抽取式环形UHF传感器的检测频段分别在1.5 GHz以下、500 MHz至1.5 GHz、1 GHz以下,且抽取式环形UHF传感器在400 MHz左右其灵敏度最高。不同绝缘缺陷的局放检测结果表明,按PRPD谱图和放电严重程度,高压导体金属尖端可分为负电晕主导、正负电晕并存、正电晕主导以及"兔耳状"阶段,认为尖端附近空间电荷在阶段转变过程中起主要作用;悬浮放电逐渐由"尖端放电阶段"转变至放电幅值、密度及相位对称的典型悬浮式放电;盆式绝缘子边遗留金属垫片将由初始类悬浮放电转变至临界闪络状态;自由金属颗粒则可分为"跳动"、"舞动"和"滑移"阶段,放电主要集中在过零点附近。高压导体金属尖端、悬浮电位和自由金属颗粒缺陷的检测灵敏度为内置式传感器最高,外置式传感器最低,而对于盆式绝缘子边遗留金属垫片缺陷则是抽取式环形UHF传感器的灵敏度最高。展开更多
基金Project Supported by Scientific Foundation for Outstanding Young Scientist of China(50425722)Natural Scientific Foundation of Chongqing(11699)
文摘The electrical tree discharge channel will be formed at concentrate spot of electric field in solid insulation dielectric,in order to study the difference of electrical tree under different electrical field,the short-cable electrode system with actual XLPE cable was designed,experiments were performed under 12 kV,15 kV,18 kV,21 kV compare to the needle-plate electrode system.Experiment results show that the electrical tree of short-cable electrode system have the same growth trend with the needle-plate electrode system in the growing characteristic,the dense of electrical tree increase with the increase of voltage level,electrical tree of short-cable electrode system growth is slower than the needle-plate electrode system at the same voltage;To get the same shape of electrical tree,the voltage of short-cable electrode system must be higher than needle-plate electrode system,the results show that the semiconductor layer and the copper shield layer outside of XLPE cable have very important affection on the electrical trees degradation.
文摘文中搭建了252 k V GIS局部放电实验平台,采用内置式、外置式UHF传感器以及自主研制的利用盆式绝缘子内部均压屏蔽环的抽取式环形UHF传感器,实验研究不同传感器的频率响应特性和在高压导体金属尖端、悬浮电位、盆式绝缘子边遗留金属垫片和自由金属颗粒等4种典型绝缘缺陷下的检测特性,并探讨了不同电压下局放的发展规律。结果表明,内置式、外置式和抽取式环形UHF传感器的检测频段分别在1.5 GHz以下、500 MHz至1.5 GHz、1 GHz以下,且抽取式环形UHF传感器在400 MHz左右其灵敏度最高。不同绝缘缺陷的局放检测结果表明,按PRPD谱图和放电严重程度,高压导体金属尖端可分为负电晕主导、正负电晕并存、正电晕主导以及"兔耳状"阶段,认为尖端附近空间电荷在阶段转变过程中起主要作用;悬浮放电逐渐由"尖端放电阶段"转变至放电幅值、密度及相位对称的典型悬浮式放电;盆式绝缘子边遗留金属垫片将由初始类悬浮放电转变至临界闪络状态;自由金属颗粒则可分为"跳动"、"舞动"和"滑移"阶段,放电主要集中在过零点附近。高压导体金属尖端、悬浮电位和自由金属颗粒缺陷的检测灵敏度为内置式传感器最高,外置式传感器最低,而对于盆式绝缘子边遗留金属垫片缺陷则是抽取式环形UHF传感器的灵敏度最高。
