采用3类特征参量比值法的铁磁谐振过电压识别

Ferro-resonance Overvoltage Identification Using Three Feature Parameters of Ratio Method

电力系统铁磁谐振过电压时常发生,持续时间长,严重危及电气设备及电网的安全运行。铁磁谐振过电压特征提取及类型识别,有助于有针对性的采取快速抑制过电压的措施,对保障电网安全可靠稳定运行具有重要的现实意义。为此,在变电站实测过电压波形基础上,根据铁磁谐振过电压发生机理及波形特征,将小波变换良好的时频局部化特性和傅里叶变换良好的频域分析能力有机结合,提取了能够有效反映铁磁谐振过电压的3类特征参量,并提出利用这3类比值识别铁磁谐振过电压的方法。该方法理论基础比较直观,识别流程清晰简单,大量现场实测数据验证了该方法在识别铁磁谐振过电压时的有效性和可靠性。

The feature extraction and recognition of ferro-resonance overvoltage is helpful for taking targeted measures to restrain overvoltage quickly,and it is of great significance to guarantee electric power system running in reliable,safe and steady status.Based on the occurring mechanism and waveform features of ferro-resonance overvoltage monitored in the substation,the wavelet transform is effectively combined with the Fourier transform so as to extract three characteristic parameters reflecting on ferro-resonance overvoltage,and a method of ferro-resonance overvoltage recognition is proposed based on the three ratios.The theoretical foundation of this method is visualized,and the identification process is simple and clear.A lot of actual data show that this method is feasible and effective in ferro-resonance overvoltage recognition.