The theoretic calculation shows the analysis mothed of wavelet packet not only can confirm the abrupt change point of the signal, but alse can confirm the fault degree and time in all frequency spectrum.

• 理论计算表明，应用小波包分析技术不仅可以确定信号的突变点，而且可以在全频范围内确定信号的突变发生的时间及程度。