表面电荷对典型聚合物绝缘材料直流闪络电压的影响  

Effect of Surface Charge on DC Flashover Voltage of Typical Polymer Insulating Materials

作　　者：高宇[1] 门业堃 杜伯学[1] 赵庆磊 

机构地区：[1]天津大学电气与自动化工程学院,天津300072 [2]国网山东省电力公司检修公司,济南250118

出　　处：《高电压技术》2015年第5期1474-1480,共7页High Voltage Engineering

基　　金：国家重点基础研究发展计划(973计划)(2014CB239501;2014CB239506);国家自然科学基金(51107087;51277131);工程电介质及其应用教育部重点实验室(哈尔滨理工大学)(编号略)~~

摘　　要：积聚在聚合物绝缘材料上的表面电荷是导致电场畸变、诱发沿面闪络的重要原因。研究表面电荷对聚合物绝缘材料沿面闪络电压的影响,对于保障电气设备的绝缘安全具有重要意义。选取聚四氟乙烯、环氧树脂和硅橡胶为试样,通过针–板电极向试样表面注入电荷,采用静电电位计测量表面电荷密度,分析表面电荷积聚、衰减特性。测量有、无表面电荷及电荷衰减过程中不同时刻的直流闪络电压,计算表面电荷对闪络电压的静态和动态影响指数Lindex和Sindex,评估表面电荷对闪络电压的影响。结果表明:充电完成时表面电荷对各材料闪络电压的影响程度为:环氧树脂>硅橡胶>聚四氟乙烯;表面电荷衰减期间其对各材料闪络电压的影响程度为:硅橡胶>环氧树脂>聚四氟乙烯。Surface charge accumulated on polymer insulating material has been considered as one of the most important reasons that are responsible for electric field distortion and thereby the reduction in flashover voltage. For the safe use of polymers in electrical equipment, tt is very necessary to understand the influence of surface charge on flashover voltage of the material. Polytetrafluoroethylene（PTFE）, epoxy resin（ER）, and silicone rubber（SiR） were employed as test samples. The surfaces of the samples were corona charged through a pair of needle-plate electrode, and surface charge density was measured by an electrostatic probe to investigate the behaviors of surface charge accumulation and decay. Flashover vol- tages under DC were measured with uncharged and charged samples, and in particular, the flashover voltages on samples during the charge decay period were obtained as well. The influence of the charge on the voltage was estimated by using both static impact index （Lmoex） and dynamic impact index （Sinoex）. It is found that at the moment when corona charging is finished, the order of surface charge influencing flashover voltage is ER〉SiR〉PTFE, however, during the period of sur- face charge decay, the order turns into SiR〉ER〉PTFE.

关 键 词：聚四氟乙烯 环氧树脂 硅橡胶 表面电荷 直流闪络电压 动态影响指数 

分 类 号：TM21[一般工业技术—材料科学与工程]