STFT和小波分析在电压暂降检测中的应用  

A wavelet transform and STFT are proposed in the application of voltage sag detection

作　　者：徐健[1] 张瑾[1] 李彦斌[1] 

机构地区：[1]西安工程大学电信学院,陕西西安710048

出　　处：《电子设计工程》2016年第24期85-87,共3页Electronic Design Engineering

基　　金：陕西省科技厅工业科技攻关项目(2015GY075)

摘　　要：对于电压暂降特征测量幅值,持续时间的准确检测是电压质量评估与抑制干扰首要解决的重要课题。本文提出基于对STFT基频幅值曲线增加阈值的新方法。分别用STFT(短时傅里叶变换),小波变换作为时频信号分析工具,针对电压暂降扰动检测问题进行对比研究。电压暂降在起始和结束时刻会产生高频信号,通过检测高频信号发生时刻来定位扰动。使用该方法可在基频幅值曲线图中直观清楚地看出扰动起始和结束时间。并对该方法的抗噪情况进行了研究。仿真结果证明,本文所提出的方法能够准确的定位电压暂降扰动,抗噪能力强,用其来检测电压暂降是一种可行有效的检测方法。In order to detect voltage sag characteristic quantity, such as amplitude and duration exactly, it is a important issue for voltage quality evaluation and disturbances suppression shuld be solved firstly. This paper proposes a new method to add a threshold value to fundamental frequency amplitude curve transformed by STFT. Using either STFT （Short-Time Fourier Transform） or wavelet transform as a time-frequency analysis tool for voltage sag detection comparative study. Voltage sags show high-frequency transients at sag initiation and at voltage recovery, we can detect the occurrence time to locate the disturbance of high frequency signal. This method detect the time at sag initiation and at voltage recovery. And I did a research about anti-noise ability. The simulation results show that the improved fundamental frequency amplitude curve can locate voltage sag disturbance exactly and have anti-noise ability, using this method to detect voltage sag is a feasible and effective.

关 键 词：电压暂降 STFT 小波变换 时频信号分析 

分 类 号：TN99[电子电信—信号与信息处理]