配电变压器低压绕组导线换位处单股匝间短路特征分析  

Characteristics Analysis of Single-strand Inter-turn Short Circuit in Low Voltage Winding Wire Transposition of Distribution Transformer

作　　者：李智 咸日常[1] 崔川 胡玉耀 郭洋 郝艳 李佳琪 LI Zhi;XIAN Ri-chang;CUI Chuan;HU Yu-yao;GUO Yang;HAO Yan;LI Jia-qi(College of Electrical and Electronic Engineering,Shandong University of Technology,Zibo 255049,China;State Grid Shandong Zibo Power Supply Company,Zibo 255000,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255049 [2]国网山东省电力公司淄博供电公司,山东淄博255000

出　　处：《水电能源科学》2023年第5期211-215,共5页Water Resources and Power

基　　金：国家自然科学基金项目(51907109)。

摘　　要：为保证电力变压器多股并绕线圈的导体长度一致、电流密度均衡,通常在其绕制过程中进行结构换位,实际运行表明导线换位处的绝缘容易损伤并导致匝间短路故障。针对实际试验中故障点难以设置、电气量无法直接检测等问题,利用“场-路”耦合原理,以型号为S13-M-200/10、低压绕组由两股扁铜线并绕、换位点在绕组中部的配电变压器为例,基于有限元仿真软件建立与实物结构尺寸相同的仿真分析模型,通过对比性能参数的实际试验值与仿真分析值,在验证模型正确性的基础上,研究电力变压器低压绕组在导线换位处发生单股匝间短路时的电气特征及电动力。研究表明,当变压器低压绕组发生单股匝间短路时,短路环内部流过数十倍额定电流的环路电流,故障相电流略有降低,有功损耗激增;导线换位引起线圈轴向力与辐向力分布不均,绕组容易失稳变形,需要对该导线换位处采取机械和绝缘加强措施。In order to ensure that the conductor length of multiple parallel coils of power transformer is consistent and the current density is balanced,the structure transposition is usually carried out in the winding process.The actual operation shows that the insulation at the conductor transposition is easy to damage and leads to inter-turn short circuit fault.Aiming at the problems that the fault point is difficult to set and the electrical quantity cannot be directly detected in the actual test,this paper uses the'field-circuit'coupling principle to take the distribution transformer with the model of S13-M-200/10,the low voltage winding is wound by two flat copper wires and the transposition point is in the middle of the winding as an example.Based on the finite element simulation software,the simulation analysis model with the same size as the physical structure is established.Through the comparison of the actual test value and the simulation analysis value of the performance parameters,on the basis of verifying the correctness of the model,the electrical characteristics and electrodynamics of the low voltage winding of the power transformer are studied when the single inter-turn short circuit occurs at the conductor transposition.The results show that when a single inter-turn short circuit occurs in the low voltage winding of the transformer,the loop current of dozens of times the rated current flows inside the short circuit ring,the fault phase current decreases slightly,and the active power loss increases sharply.Conductor transposition causes uneven distribution of axial force and radial force of the coil,and the winding is prone to instability and deformation.It is necessary to take mechanical and insulation strengthening measures at the conductor transposition.

关 键 词：配电变压器 低压绕组 两股并绕 导线换位 匝间短路 电动力 

分 类 号：TM411[电气工程—电器]