摘要
油纸电容型套管是大型电力变压器的重要部件,其安全可靠性是电网稳定运行的关键因素。变压器出线套管结构复杂、设计紧凑,在安装设计不当,运行环境恶劣等条件下很容易成为变压器绝缘系统的最薄弱环节。统计表明,25%以上的电力变压器故障是由套管绝缘故障导致的,而套管绝缘受潮导致的事故案例居于套管绝缘故障类型中的前列。因此,对套管绝缘状态的有效评估显得尤为重要。为探究水分对油纸绝缘套管的影响,运用介电响应法,结合在实验中测量得到的单层油纸绝缘的结果,仿真得到简化套管均匀受潮时介电谱。并运用Kramer-Kroning方程将得到的介电谱虚部分解为电导损耗部分和极化损耗部分,观察各个部分随水分变化规律,总结为如下两点:第一是电导损耗分量随水分的增大急剧增大,变化量可以达到好几个数量级,且电导损耗随水分变化其趋势基本不会发生改变;第二,油纸中水分的加入使油纸出现了新的极化过程,在介电谱中0.1~10 Hz出现一个损耗峰,且损耗峰幅值随水分增大而增加。
The oil-immersed paper capacitive bushing is an important part of a large power transformer and its safety and reliability are key factors for stable operation of power grids. As the outgoing bushing of the transformer is complicated in structure and compact in design,it can easily become the weakest link in the insulation system of the transformer under the conditions of improper design and installation as well as unfavorable operation. The relevant statistics show that more than 25% of transformer faults are caused by the insulation failure of the bushings,and the accidents caused by moisture effects on the insulation rank in the forefront of the failure types of bushings. Therefore,it is very important to evaluate the insulation status of bushings effectively. In order to explore the influence of water on the oil-immersed paper insulating bushing,we used the dielectric response method combined with the results of the single-layer oil-immersed paper insulation measured in the experiment to obtain through simulation a simplified dielectric spectrum of the bushing affected by moisture uniformly. And we used the Kramer-Kroning equation to divide the obtained dielectric spectrum into the conductance loss part and the polarization loss part,and then observed the change law of each part with moisture changes. The conclusion can be summarized as follows: first, the component of conductance loss sharply increases with increase of moisture,and the change can reach several orders of magnitude,and the trend of the change remains unchanged basically;second,the addition of water in the oil-immersed paper causes a new polarization process and a loss peak occurs at about 0.1~10 Hz in the dielectric spectrum and the loss peak amplitude is increased with the increase of water content.
作者
李君
杨凯歌
谢佳成
胡一卓
任明
董明
LI Jun;YANG Kaige;XIE Jiacheng;HU Yizhuo;REN Ming;DONG Ming(Modern Electric Power Research Institute,North China Electric Power University,Beijing 100001,China;State Key Laboratory of Electrical Insulation for Power Equipment,Xi’an Jiaotong University,Xi’an 710049,Shaanxi,China)
出处
《电网与清洁能源》
2020年第11期1-7,共7页
Power System and Clean Energy
基金
国家自然科学基金项目(U1866603)。
关键词
油纸绝缘套管
受潮检测
频域介电响应
电导
极化
oil-immersed paper insulating bushing
moisture detection
frequency domain dielectric response
conductance
polarization
