基于小波能量的变压器励磁涌流识别方法

提出了一种基于小波能量变化实现励磁涌流判别的新方法。由于励磁涌流和内部故障电流产生的机理不同,因此其能量分布是不同的。小波变换能够准确捕捉暂态信号的特征,且小波能量能够反映信号能量在时域的分布情况。采用db4作为母小波对电力系统仿真所产生的大量实验数据进行了小波变换,通过提取小波变换后的d4（第四层细节部分）并计算其能量变化情况,制定了合理的判据。实验结果表明,该方法能够准确、迅速地识别出变压器励磁涌流状态。

Method for Inrush Current Detection in Transformers Based on Wavelet Transform Energies

How to distinguish between inrush and internal fault currents is always a key problem in power transformer current differential protection.This paper has demonstrated a new method which based on the change in wavelet transform energies to identify inrush.Inrush and internal fault currents have different energy distribution because of the different essence between them.The transient characters can be detected accurately by wavelet transform and the wavelet energies can reflect the energy distribution of the ...