摘要
由于高压复合绝缘子受模压、材料热胀冷缩特性、密封加工工艺等因素的影响,在金具、芯棒和伞裙护套之间容易产生局部微间隙,从而造成局部放电,导致复合绝缘子的耐老化性能降低.将复合绝缘子的静电场无界域问题等效为分层均匀媒质的多介质闭域电场问题,建立三维复合绝缘子模型,采用有限元方法对存在局部微间隙的复合绝缘子的电气性能进行分析,研究局部微间隙不同尺寸及位置对局部和整体电位、电场强度分布的影响规律.结果 表明:局部微间隙邻近的3片伞裙的电场强度发生明显畸变,而对其余伞裙的影响可以忽略;局部微间隙尺寸增大将导致相应伞裙的电压承担率增加,球形微间隙表面的场强最大值也逐渐升高,导致微间隙内部区域放电几率增大.
Due to the influence of moulding pressure,thermal expansion and contraction of materials,sealing processing technology and other facloc,the high-voltage composite insulatora are prone to produce local micro-gap between metal fittings,mandrels and umbrella skirt sheaths,which results in partial discharge and decreases the aging resistance of composite insulators.With the FXBW4-110/10()type composite insulator as an example,this paper makes the unbounded electrostatic field of the composite insulator equivalent to the multi-medium closed electrostatic field of multi-layered homogeneous media,and constructs a 3-dimention model of the insulator,and studies the electrical characteristics of the composite insulator with lhe partial micro-gap based on lhe finite element method,and analyzes the influence of the local and overall potential distribution and electric field lor different micro-gap sizes and positions.The results show that the partial micro-gap exerts obvious impacts on the potential distribution of the first umbrella skirt al the high-end and low-end,the field strength of the three umbrella skirts around the micro-gap gets distorted seriously,while the effects on other umbrella skirts can be neglected;the voltage between the micro-gaps improves rapidly with increase of the micro-gap size,and the maximum electric field intensity on the surface of the spherical micro-gap gradually increases,leading to an increase of the probability of i^tenial discharge in the micro-gap.
作者
钱文姝
刘严
曹志
黄伟
樊平
王庆丰
汪适文
陈娟
周冬
QIAN Wenshu;LIU Yan;CAO Zhi;HUANG Wei;FAN Ping;WANG Qingfeng;WANG Shiwen;CHEN Juan;ZHOU Dong(State Grid Shaanxi Electric Power Research Institute,Xi'an 710100,Shaanxi,China;State Crid Corporation of China,Beijing 100031,China;Jingmcn Power Supply Company,State Grid Hubci Electric Power Company Limited,Jingmcn 448000,Hubei,China;College of Electrical and New Energy,Three Gorges University,Yichang 443000,Hubei,China)
出处
《电网与清洁能源》
2019年第6期16-22,共7页
Power System and Clean Energy
基金
国家自然科学基金(61876097)~~
关键词
复合绝缘子
局部微间隙
有限元法
场强
电位分布
composite insulator
partial micro-gap
finite clement method
electric field
potential distribution
