基于能量频域分布的励磁涌流识别方法  

Magnetizing Inrush Identification Method Based on Energy Distribution in the Frequency Domain

作　　者：陈星宇[1] 代陵通 钟应 袁冰玉 Chen Xingyu;Dai Lingtong;Zhong Ying;Yuan Bingyu(College of Electrical Engineering,Chongqing University,Chongqing Sichuan 400044,China;State Grid Chongqing Electric Power Co.Nan’an Power Supply Branch,Chongqing Sichuan 401336,China)

机构地区：[1]重庆大学电气工程学院,重庆400044 [2]国网重庆市电力公司南岸供电分公司,重庆401336

出　　处：《电气自动化》2020年第3期103-104,118,共3页Electrical Automation

摘　　要：准确区分励磁涌流与故障电流是确保变压器保护性能的关键环节。通过对变压器励磁涌流与故障电流整体频域特性的分析,提出了一种基于差动电流能量分布的励磁涌流判据。首先采用能降低噪声干扰的矩阵束算法,辨识差动采样电流的频域参数,从而计算电流能量分布熵与能量标准差的比值。然后结合故障电流与励磁涌流由不同频域分量构成的特点,通过对比差动电流和正弦信号的频域能量分布特性以区分励磁涌流和短路电流。通过PSCAD/EMTDC软件仿真分析,证明了新判据能够正确地识别包括对称性涌流在内的励磁涌流,并且具备有效抑制噪声影响的优点。Accurate discrimination of magnetizing inrush current and fault current is crucial to the guarantee of transformer protection performance.A criterion for discrimination of inrush current was proposed on the basis of a differential current energy distribution through an analysis of the frequency domain characteristics of the transformer inrush current and fault current.Firstly,frequency domain parameters of the differential sampling currents were identified through the matrix pencil algorithm which could reduce noise interference,so that the ratio between the distribution entropy of current energy and standard energy deviation might be calculated.Then,inrush current and short-circuit current were discriminated through comparison of frequency domain energy distribution features of differential current and sinusoidal signal under consideration of the fact that fault current and inrush current were composed of different frequency domain components.Simulation analysis based on PSCAD/EMTDC software proved that the proposed criterion could identify magnetizing inrush current including symmetric inrush currents and could suppress noise impact effectively.

关 键 词：变压器 差动保护 励磁涌流 能量分布 矩阵束算法 频域 

分 类 号：TM772[电气工程—电力系统及自动化]