基于改进S变换-TT变换的电压暂降特性研究

Research of voltage sag based on improved S-transform-TT transform

针对S变换的窗函数固定,以及在检测扰动信号的起止时刻、幅值变化、相位变化时的检测精度不高的问题,在S变换中引入两个调谐因子,得到一种改进的S变换,并对改进的S变换进行傅里叶反变换得到TT变换,将改进的S变换与TT变换相结合应用到主要引起电压暂降的3种暂降源中,并在MATLAB软件上对这3种暂降扰动源信号进行了仿真分析。仿真结果表明,所提的方法比使用S变换方法在检测电压暂降信号上具有更高的检测精度和更好的效果,为更好地提取暂降特征信息以及暂降源的识别打下基础。

In view of the fixed window function of S-transformation and the problem of detection accuracy when detecting the start and end moments of disturbance signal,amplitude variation,and phase change,this paper introduces two tuning factors in S-transformation to obtain an improved one.S transform,and the inverse transform of the improved S transform to get the TT transform,the improved S transform and the TT transform are applied to the three sources of the disturbance that mainly cause the voltage sag,and on the MATLAB to the three a kind of temporary disturbance source signal was detected and analyzed.The MATLAB simulation results show that the proposed method has better effect and higher detection precision than the S-transform method in detecting voltage sags,which lays the foundation for better extraction of the characteristics of sags and identification of temporary sources.