【摘要】 采用小波包与傅立叶变换相结合的方法 ,对尾水管振动信号进行小波包多层分解 ,以提取信号的低频特征信息 ,然后进行精确的频谱分析取得涡带的特征频率。仿真实验表明 ,该方法能利用小波包时频局部聚焦分析能力 ,有效提取尾水管微弱低频特性信息 ,对尾水管振动故障提供早期预诊手段更多还原

【Abstract】 The hydraulic fluctuating signal in the draft tube includes low-frequency information that is relative to vortex, and traditional FFT is hard to distill frequency spectrum of the information. Using the way of combining Wavelet Packet with FFT, the signal in the draft tube can be decomposed to multilayer, and its characteristic information of fault can be distilled. Accordingly we can carry out accurate analysis of frequency spectrum. We can distill the characteristic frequency of the vortex. Because Wave Packet can focus and analyze part-time frequency, the simulating results show that the way is effective to distill weak information of fault and implement early diagnosis.更多还原