小波变换识别变压器励磁涌流和故障电流的新方法

A new wavelet transform approach to discriminate magnetizing inrush current and fault current

利用小波变换对变压器两侧的电流信号进行分解,得到突变点的故障跳乘积符号,从而准确地区分励磁涌流和故障电流。利用实时数字仿真器(RTDS)对不同内部故障类型和励磁涌流进行了仿真,算法不受最严重故障(带故障空载投入)以及严重CT饱和情况的影响。

Current signals at both sides of transformer are analyzed by wavelet transform.The sign of fault jump′s product is used to discriminate magnetizing inrush current and fault currents.Different types of internal faults and magnetizing inrush are simulated by Real-time Digital Simulator(RTDS), this approach is not affected by the sever fault that transformer is energized without load when internal fault occurs and CTs saturate.