变压器励磁涌流闭锁逻辑优化方案  

Excitation Inrush Current Blocking Logic Optimization Scheme of Transformer

作　　者：周浩 石磊 吕强 ZHOU Hao;SHI Lei;LYU Qiang(CYG SUNRI Co.,Ltd.,Shenzhen Guangdong 518057,China)

机构地区：[1]长园深瑞继保自动化有限公司,广东深圳518057

出　　处：《浙江电力》2020年第11期68-74,共7页Zhejiang Electric Power

基　　金：内蒙古电力(集团)有限责任公司包头供电局科技项目(BG-ZXZB-2018-XSGL2C0101-2100)。

摘　　要：变压器在空载合闸时会产生励磁涌流,由于空载合闸角、剩磁以及变压器结构材料和制造工艺的差异导致励磁涌流存在较大差异,可能存在低谐波比的情况,使得常规的励磁涌流判据可能无法有效闭锁差动保护。结合工程中空投变压器导致差动保护动作的案例,分析总结出特殊工况下励磁涌流的特征,在原励磁涌流逻辑基础上,提出采用"3取2"复合制动、相电流谐波判据和最大相谐波判据的综合制动逻辑,解决了工程中遇到的无法识别低谐波比励磁涌流的问题,最后通过仿真和工程实例验证了该优化方案的优越性。The magnetizing inrush current is generated in the transformer no-load closing.The no-load closing angle,residual magnetism and differences in transformer structural materials and manufacturing processes lead to large differences of excitation inrush current.Therefore,conventional excitation inrush current criterion may not effectively block differential protection due to low harmonic ratio.In view of the cases of differential protection action caused by a no-load transformer in engineering practice,excitation inrush characteristics under special operation condition is analyzed and summarized.Based on the original excitation inrush logic,the paper proposes an integrated braking logic comprising"two-out-of-three"braking,phase current harmonic criteria and the maximum phase harmonic criteria,which solves the identification failure of excitation inrush with low harmonic ratio.The superiority and advancement of the scheme are proved by simulation and engineering application.

关 键 词：励磁涌流 相电流判据 最大相谐波判据 改进与优化 

分 类 号：TM774.1[电气工程—电力系统及自动化]