利用希尔伯特边际谱鉴别变压器励磁涌流

Identification of Transformer Inrush Current Based on Hilbert Spectrum

根据励磁涌流中有很大成分的高次谐波和非周期分量,而故障电流基本保持基频正弦波的特点,研究了一种利用希尔伯特边际谱来辨别变压器励磁涌流和故障电流的新方法。该方法利用希尔伯特黄变换对电流信号按频率分离,对额定频率段的希尔伯特边际谱幅值进行积分,根据积分值与整定值关系可鉴别信号电流。经PSCAD/EMTDC和MATLAB仿真软件对大量样本的仿真验证,该方法能精确地实现变压器励磁涌流与故障电流的可靠区分。

Inrush current contains a large component of higher harmonic and aperiodic components,while fault current always keeps its basic frequency.Aiming at this frequency feature,a new method to distinguish inrush current and fault current based on Hilbert spectrum is studied.It uses Hilbert spectrum to separate signal frequency,and calculates Hilbert spectrum amplitude of rated frequency by integral.Based on the relationship between integral results and setting value,it can distinguish current signal.PSCAD/EMTDC and MATLAB are used to complete simulation samples.It is proved that this method can distinguish inrush current and fault current reliably.