FXBW4-35/70绝缘子覆冰特点及污秽闪络特性研究  

Study on Icing Characteristics and Pollution Flashover Characteristics of FXBW4-35/70 Insulator

作　　者：胡聪 王岩 石俏 梁新福 党世轩 罗日成[2] HU Cong;WANG Yan;SHI Qiao;LIANG Xin-fu;DANG Shi-xuan;LUO Ri-cheng(Foshan Electric Power Bureau,China Southern Power Grid,Foshan 528000,China;College of Electrical and Information Engineering,Changsha University of Science and Technology,Changsha 410114,China)

机构地区：[1]广东电网有限责任公司佛山供电局,广东佛山528000 [2]长沙理工大学电气与信息工程学院,长沙410114

出　　处：《电力学报》2021年第4期315-324,共10页Journal of Electric Power

基　　金：广东电网有限责任公司科技项目资助(项目编号GDKJXM20184782)

摘　　要：研究了绝缘子表面覆冰水由液态至固态相变过程中“晶释效应”对覆冰水中电解质和杂质重新分布的影响,以及绝缘子串覆冰后冰凌桥接伞裙造成绝缘子串电压分布的畸变,致使绝缘子串闪络电压降低并引发冰闪。通过研究绝缘子的覆冰闪络的发生机理,可为绝缘子的选择及覆冰防范工作提供参考。采用COMSOL软件中的“感应/直流耦合放电”多物理场接口来研究绝缘子的覆冰闪络特性,并用磁流体动力学方程(MHD)即质量守恒方程、动量守恒方程和能量守恒方程来描述整个过程中复杂的能量变化。以覆冰状态下的复合绝缘子为研究对象,通过仿真软件建立了基于电场、磁场、层流场、传热场的多物理场耦合仿真模型,分析覆冰厚度、冰面水膜对绝缘子冰闪电压的影响。结果表明,随着覆冰厚度的增加,绝缘子的电气强度持续下降。当覆冰厚度超过15 mm~20 mm后,绝缘子的电气强度不再显著变化;存在冰面水膜的绝缘子的电气强度明显低于冰面无水膜的绝缘子;随着覆冰厚度的增加,存在冰面水膜的绝缘子的电气强度下降速度快于冰面无水膜的绝缘子。采用了三个特征参数评估绝缘子的电气强度,分别为平均电场强度E_(av)、最大电场强度_(Emax)和平均电场能E_(1)。这三个特征参数值越小则绝缘子的电气状态愈好。由于绝缘子串伞裙被冰凌桥接后,使得爬距失效,从而降低了闪络梯度,进而导致闪络事故的发生。因此,在绝缘子串覆冰过程中,需要采取能够阻隔冰凌桥接形成的有效措施,为解决此问题提出了间插布置大盘径绝缘子以防止覆冰绝缘子冰凌桥接的形成,并在绝缘子表面涂憎水性能的涂料,以最大限度减少冰层黏着力。通过以上措施可以有效改善绝缘子覆冰闪络。The influence of“crystal release effect”on the redistribution of electrolyte and impurity in ice water during the phase transition from liquid to solid state on insulator surface was studied,and the voltage distribution of insulator string was distorted by the ice bridge after the insulator string was coated with ice,which leaded to the flashover voltage of insulator string reduced and the ice flash was happened.By studying the mechanism of insulator icing flashover,it could provide reference for insulator selection and icing prevention.The“induction/DC coupling discharge”multi-physical field interface in COMSOL software was used to study the ice-covered flashover characteristics of insulators,and the magnetohydrodynamic equation(MHD),namely the mass conser⁃vation equation,momentum conservation equation and energy conservation equation,was used to describe the complex energy changes in the whole process.Taking composite insulators under ice condition as the research object,a multi-physics field coupling simulation model based on electric field,magnetic field,laminar flow field and heat transfer field was established by simulation software to analyze the effects of ice thickness and ice water film on the ice lightning voltage of insulators.The results showed that the electrical strength of the insulator de⁃creased continuously with the increase of the ice thickness.When the ice thickness exceeds 15 mm~20 mm,the electrical strength of the insulator did not change significantly.The electrical strength of insulators with water film on ice surface was obviously lower than that without water film on ice surface.With the increase of ice thick⁃ness,the electrical strength of insulators with water film on ice surface decreased faster than that without water film on ice surface.Three characteristic parameters were used to evaluate the electrical strength of the insulator,which were the average electric field intensity E_(av),the maximum electric field intensity E_(max) and the average elec⁃tric field energy

关 键 词：绝缘子 数值模拟 冰闪电压 覆冰厚度 冰面水膜 晶释效应 

分 类 号：TM216[一般工业技术—材料科学与工程]