自耦变压器投入导致距离保护误动分析及改进  

Analysis and Improvement of Distance Protection Maloperation Caused by Autotransformer Input

作　　者：林国松[1] 张硕 权伟[1] 李原 LIN Guosong;ZHANG Shuo;QUAN Wei;LI Yuan(School of Electrical Engineering,Southwest Jiaotong University,Chengdu 610031,China)

机构地区：[1]西南交通大学电气工程学院,成都610031

出　　处：《电力系统及其自动化学报》2022年第9期146-152,共7页Proceedings of the CSU-EPSA

基　　金：四川省自然科学基金资助项目(2022NSFSC0405)。

摘　　要：为研究涌流对牵引变电所距离保护的影响,本文对1次单线AT供电线路的分区所自耦变压器合闸导致牵引变电所距离保护误动作情况进行分析。根据本次误动线路搭建电路模型,理论分析励磁涌流及和应涌流产生的原因,并对故障前后的电压、电流波形进行阻抗与谐波分析,得出了牵引变电所距离保护误动作的原因。为了避免牵引变电所距离保护误动作再发生,提出采用3次谐波闭锁距离保护的改进方案,可有效避免因2次谐波闭锁失效导致的距离保护误动。基于Matlab/Simulink仿真验证了改进方案的可行性。To study the influence of inrush current on the distance protection in a traction substation,the distance protection maloperation in the traction substation caused by the closing of an autotransformer in the section post of a single AT power supply line is analyzed in this paper.A circuit model is established according to the affected line,and the causes of excitation inrush current and sympathetic inrush current are analyzed theoretically.In addition,the voltage and current waveforms before and after the fault are analyzed from the aspects of impedance and harmonics,and the cause of distance protection maloperation in the traction substation is discussed.To avoid the recurrence of similar situations,an improved scheme for the third harmonic restraint distance protection is proposed,which can effectively avoid the distance protection maloperation caused by the failure of second harmonic restraint.The simulation results based on Matlab/Simulink verify the feasibility of the improved scheme.

关 键 词：自耦变压器 3次谐波闭锁 综合谐波抑制 励磁涌流 和应涌流 

分 类 号：U224.4[交通运输工程—道路与铁道工程]