基于磁通频域特征的变压器励磁涌流识别新方法  

Identification of transformer magnetization inrush current based on frequency-domain characteristics of Magnetic flux

作　　者：孙洋[1] 黄家栋[1] 

机构地区：[1]华北电力大学电力系统保护与动态安全监控教育部重点实验室,河北保定071003

出　　处：《华北电力大学学报（自然科学版）》2011年第1期21-25,共5页Journal of North China Electric Power University：Natural Science Edition

摘　　要：基于变压器在空投或故障情况下磁通频域特征的不同,提出一种利用磁通对电流导数中偶次谐波制动比和基频幅值大小来判别励磁涌流和故障电流的新方法。通过推导发现故障时磁通对电流导数中偶次谐波成分明显高于奇次谐波成分,而涌流时则没有此特征。在此基础上,给出了两个判据并分别定义两个逻辑变量M和N,根据两个逻辑变量的乘积来判断变压器是否发生励磁涌流。该方法原理简单,易于实现,无任何先验参数。动模试验分析结果表明该方法能有效区分励磁涌流和故障电流,并对轻微匝间故障也有足够的灵敏度。Based on frequency-domain characteristics of flux when a transformer is switched on and energized or fault occurs.A new method for distinguishing magnetizing inrush is proposed by means of the restraint ratio of even harmonics and the magnitude of the fundamental frequency amplitude of flux-current derivative.Theoretical derivation shows the value of even harmonics are higher than that of odd harmonics in flux-current derivative under internal fault,however,without this feature under inrush current.Two criterion and logical variables M and N are further presented based on the proposed method.According to the product of two logical variables to determine whether there has transformer magnetizing inrush current.This method is simple in principle,easy implementation,no need of anticipated internal parameters,the experimental results indicate that the proposed principle is reliable and sensitive to low level turn-turn faults.

关 键 词：变压器 励磁涌流 内部故障 磁通对电流导数 偶次谐波制动比 

分 类 号：TM401.1[电气工程—电器]