接地变抗出口短路能力分析及提升  

Analysis and improvement of grounding transformer′s ability to resist outlet short-circuit

作　　者：李嘉洋 咸日常[1] 李飞 胡玉耀 薛永端[3] 王玮[1] LI Jiayang;XIAN Richang;LI Fei;HU Yuyao;XUE Yongduan;WANG Wei(College of Electrical and Electronic Engineering,Shandong University of Technology,Zibo 255000,China;State Grid Shandong Electric Power Company Zibo Power Supply Company,Zibo 255000,China;College of New Energy,China University of Petroleum(East China),Qingdao 266580,China)

机构地区：[1]山东理工大学电气与电子工程学院,山东淄博255000 [2]国网山东省电力公司淄博供电公司,山东淄博255000 [3]中国石油大学(华东)新能源学院,山东青岛266580

出　　处：《电力工程技术》2024年第4期226-234,共9页Electric Power Engineering Technology

基　　金：国家自然科学基金资助项目(52077221)。

摘　　要：针对目前接地变出口短路工况下绕组物理特征研究不足、损坏事故多等问题,文中以一台干式接地变为研究对象,利用有限元仿真软件搭建三维多物理场耦合模型,分析研究接地变低压侧出口短路工况下绕组电磁、温升、应力形变等多物理参量的变化及分布规律,探究影响接地变抗出口短路能力的关键因素。结果表明:接地变发生出口短路后,受其轭铁心及邻柱铁心的影响,绕组侧面磁通及其等效应力均大于绕组正面,整体形变极不均匀;受接地变特殊的绕组结构和工作方式的影响,其低压绕组在出口短路故障时的暂态温度可达140.9℃,远高于高压绕组。最后基于动、热稳定的双重约束,提出接地变抗出口短路能力的提升措施,对接地变抗出口短路能力的薄弱部位进行结构优化。Currently,there are issues such as insufficient research on the physical characteristics of windings in grounding transformers under outlet short circuit conditions and a high number of damage accidents.Given this issues,a dry-type grounding transformer is chosen as the research subject.A three-dimensional multi-physics field coupling model is constructed using finite element simulation software.The aim is to analyze changes and distribution patterns of multiple physical parameters such as winding electromagnetic fields,winding temperature rise,and winding stress deformation under the outlet short circuit condition of the low voltage side of the grounding transformer.The key factors influencing grounding transformer′s ability to resist outlet short circuit are also explored.Results indicate that after an outlet short circuit occurs in the grounding transformer,the magnetic flux and equivalent stress on its winding side,influenced by its yoke core and adjacent pillar cores,are greater than those on the front side,resulting in extremely uneven overall deformation.Due to the grounding transformer′s special winding structure and operating mode,the transient temperature of its low voltage winding during outlet short circuit faults can reach 140.9℃,which is much higher than that of the high voltage winding.Finally,measures are proposed to improve the grounding transformer′s ability to resist outlet short-circuit based on the dual constraints of dynamic and thermal stability,and structural optimization is carried out for the weak areas of grounding transformer to resist outlet short-circuit.

关 键 词：接地变 出口短路 多物理场耦合 绕组形变 绕组温升 抗短路能力提升 

分 类 号：TM41[电气工程—电器]