基于S变换与全局最优阈值的暂态扰动信号降噪

Transient disturbance signals de-noising based on S-transform and optimal global threshold

现有的电能质量扰动信号降噪处理方法容易损失信号中包含的高频暂态扰动细节。提出一种基于S变换与全局最优阈值的扰动信号降噪方法。首先,通过S变换获得扰动信号的时-频矩阵;其次,将S变换模矩阵转化为灰度表示;之后,采用Otsu’s算法,计算全局最优阈值,进行滤波降噪;最后,将降噪后的时-频矩阵进行S变换逆变换获得降噪后的扰动信号。仿真实验证明,新方法能够有效保留信号中的高频扰动成分,降噪效果好,能够满足扰动信号分析要求。

The details in the high frequency area of transient disturbances signals are always destroyed by current the signal de-noising methods. A new approach of disturbance signals de-nosing based on S-transform and local optimal global threshold has been proposed in this paper. Firstly, the time-frequency matrixes of disturbances signals were cal- culated by the S-transform. Secondly, the amplitudes of S-transform modular matrix were transformed to grey level presentation. Then, the optimal global threshold was chosen by Otsu＇ s algorithm, and the thresholds were used to de- noise the disturbance signals. Finally, the time-frequency matrix after de-noising was transformed into disturbances signals by invert S-transform. The simulation results show that the new method can remain the high frequency elements of the disturbances effectively with excellent de-nosing ability. It could satisfy the requirements of disturbance analysis. signals