以电场特征理解电缆终端气隙的局部放电发展机理

发布时间：2018-06-13 22:18

本文选题：电缆终端 + 气隙缺陷　；参考：《高电压技术》2014年12期

【摘要】：为了研究气隙缺陷导致电缆终端绝缘失效的机理,基于电场分析探讨了终端气隙的局部放电发展过程。建立了终端气隙缺陷的有限元模型并进行了电场理论计算,阐述了气隙对终端电场分布的影响并分析了气隙沿电缆轴向和径向的电场强度特征,讨论了气隙参数与终端气隙内电场强度最大值之间的关系。进而,通过实验终端电热老化实验中的局部放电检测发现,运行条件下终端气隙缺陷放电迅速发展,在不同的老化阶段表现出不同的放电特征。同时,观察老化前后的气隙缺陷发现,老化后气隙内的绝缘毛刺被烧蚀,通道狭长平滑。结合气隙的电场特征分析说明,半导电层截断位置集中的电场导致此处的气隙更容易发生局部放电,而放电表现出的阶段性差异与气隙通道的逐渐贯穿密切相关,通过简化的放电模型可以描述气隙的放电发展机理。
[Abstract]:In order to study the mechanism of terminal insulation failure caused by air gap defect, the development process of partial discharge of terminal air gap is discussed based on electric field analysis. The finite element model of air gap defect is established and the electric field theory is calculated. The influence of air gap on terminal electric field distribution is expounded and the electric field intensity characteristics along the axial and radial direction of air gap are analyzed. The relationship between the air gap parameters and the maximum electric field intensity in the terminal air gap is discussed. Furthermore, through the partial discharge detection in the electrothermal aging experiment of the terminal, it is found that the terminal gap defect discharge develops rapidly under the condition of operation, and shows different discharge characteristics in different aging stages. At the same time, the air gap defects before and after aging were observed, the insulation burr in the air gap was ablated after aging, and the channel was long and narrow smooth. Combined with the analysis of the electric field characteristics of the air gap, it is shown that the electric field at the truncated position of the semiconductive layer leads to the partial discharge of the air gap, and the phase difference of the discharge is closely related to the gradual penetration of the air gap channel. The development mechanism of air gap discharge can be described by simplified discharge model.
【作者单位】：四川大学电气信息学院;国网宁夏电力公司电力科学研究院;
【基金】：国家自然科学基金(51477106)~~
【分类号】：TM75

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