The wavelet packet theory has the good hour-frequency characteristic, it can be availably used for the noise suppression processing of the digital signal and withdrawing the signal characteristic.
小波包分析具有优良的时频特性，可以有效地用于数字信号的消噪处理和对信号进行特征提取。
2
To the scheme of mechanical on load tap changer combined with thyristors, its characteristic of arc suppression is analyzed in details, and a corrected scheme is then present.