基于小波理论的变压器励磁涌流的研究

变压器差动保护受励磁涌流的影响，针对这一因素，该文提出一种基于小波变换的变压器励磁涌流识别新方法。首先分析了单相变压器励磁涌流的产生机理，其次使用MATLAB提供的电力系统工具箱PSB建立励磁涌流与区内故障电流的仿真模型，并脂db5小波对电流信号进行3尺度分解，仿真结果表明，小波变换系数能准确反应励磁涌流波彤的突变，最后根据仿真结果提出一个励磁涌流识别判据。

Study on Transformer Inrush Current Based on Wavelet Transform

Transformer differential protection is affected by inrush current.Aiming at this factor,this paper proposes a new method to identify inrush current based on wavelet transform.Firstly,it analyses the produc- tion mechanism of a single phase transformer.Then,the simulation models of inrush current and internal fault current are built by PSB software provided by MATLAB software.At that time,db5 wavelet is choosen to complete a 3-scale decomposition of current waveform.Simulation result show that the wavelet transform coefficients can reflect the degradation of inrush current.At last,this paper proposes a new identification judgement based on the simulation result.