短时电压扰动检测与定位新方法

A new method to detect and locate instantaneous voltage disturbances

提出了基于奇异值分解技术的短时电压扰动检测方法。根据短时电压扰动的电压采样序列构造Hankel矩阵,并对该矩阵进行奇异值分解;基于该分解结果将原电压信号分解到多个分解层,得到信号的一种线性分解,在某些分解层上电压扰动起点和终点表现为突变,根据这些突变可以定位扰动起始和结束时刻。从原采样序列中,在起点两侧分别提取一个周波信号进行FFT运算以获取扰动发生前后的基波幅值,基于两者幅值关系可以确定扰动的类型,并计算出其指标。搭建了短时电压扰动信号的模拟电路,并基于LabVIEW虚拟仪器检测平台建立实验系统,实验结果证明了所提方法的有效性,且比小波变换方法优越。

A characteristic method for voltage disturbances based on singular value decomposition is proposed.Hankel matrix is constructed using the time series of voltage signal.Then singular value decomposition is executed to the Hankel matrix and the decomposition of the voltage signal is calculated.At every decomposition layer,the start point and the end point show prominence and then they can be detected.At each side of the start point in the original signal,one cycle signal is taken out to calculate the fundamental component by FFT.The type of the voltage disturbance can be gotten by the relationship between the fundamental components and the index can also be gotten.A circuit to simulate instantaneous voltage disturbance is made.Experiment system is set up based on LabVIEW and data acquisition system.The experiment results show the correctness of the method and its superiority over the wavelet.