摘要
干式变压器低压绕组的匝间绝缘故障不易通过外观表征直接发现,且难以实现实时监测,严重影响供电可靠性。针对干式变压器低压绕组单匝匝间短路故障时的电磁特征研究不足而导致故障检测方法缺失及实际研究中难以设置绕组匝间短路故障的问题,利用有限元仿真软件建立与实际干式变压器一致的“场-路”耦合模型,并验证了该模型在额定运行工况下的准确性。在此基础上探究低压绕组发生匝间短路故障时其短路点电流、短路匝电流、短路匝电流密度及短路匝辐向磁密和轴向磁密等电磁参数的变化规律,研究在绕组不同位置发生匝间短路故障时短路匝所受电动力的分布情况。结果表明,绕组不同位置发生匝间短路时,磁密最大值出现在最外层短路匝;最外层短路匝所受辐向力最大,最内层短路匝所受轴向力最大。研究结果为干式变压器匝间绝缘在线监测和保护技术提供了理论依据,有利于抗短路能力提升措施的研究与实施。
The low voltage winding interturn insulation fault of dry-type transformer is not easy to find directly through the appearance of the phenomenon,and is difficult to real-time monitoring,seriously affecting the safe and stable operation of power systems.In view of the lack of fault detection methods due to insufficient research on the electromagnetic characteristics of single-turn interturn short-circuit faults in low-voltage windings of dry-type transformers,and the difficulty in setting interturn short-circuit faults in practical projects,finite element simulation software was used to establish a field-circuit coupling model which is consistent with the actual dry-type transformer,and the accuracy of the model was verified under rated operating conditions.On this basis,the variation rules of electromagnetic parameters of short-circuit turns at different positions were explored when interturn short-circuit faults occur in low-voltage windings.The distribution of electromagnetic force on short-circuit turns when interturn short-circuit faults occur in windings at different positions was simulated.The results show that when the interturn short circuit occurs at different positions of the winding,the maximum magnetic density appears in the outermost short-circuit turn;the outermost short-circuit turn is subjected to the largest radial force,and the innermost short-circuit turn is subjected to the largest axial force.Therefore,it provides a theoretical basis for on-line monitoring and protection technology of dry-type transformer interturn insulation,which is conducive to the research and implementation of measures to improve short-circuit resistance.
作者
郝艳
咸日常
胡玉耀
张海强
郭洋
李佳琪
HAO Yan;XIAN Ri-chang;HU Yu-yao;ZHANG Hai-qiang;GUO Yang;LI Jia-qi(School of Electrical and Electronic Engineering,Shandong University of Technology,Zibo 255000,China;Zibo Power Supply Company,State Grid Shandong Electric Power Company,Zibo 255000,China)
出处
《水电能源科学》
北大核心
2023年第8期214-218,共5页
Water Resources and Power
基金
国家重点研发计划(2017YFB0902800)。
关键词
干式变压器
有限元仿真
匝间短路
电磁特征
电动力
dry-type transformer
finite element simulation
interturn short circuit
electromagnetic characteristics
electric power
