基于局部均值分解的电压暂降检测新方法  

New Detection Method for Voltage Sags Based on Local Mean Decomposition

作　　者：胡标 王晓光 吴素敏 吴丽娜[2] 

机构地区：[1]国网浙江省云和县供电公司,浙江云和323600 [2]华北电力大学,河北保定071003

出　　处：《计量学报》2015年第6期622-627,共6页Acta Metrologica Sinica

基　　金：科技部技术创新基金项目(13C26211300469)

摘　　要：提出了利用局部均值分解（LMD）方法对电压暂降进行检测和分析的新方法，该方法利用分解所得的瞬时幅值和瞬时频率进行电压暂降幅值、频率的检测以及扰动起止时刻的定位。针对LMD方法存在的“端点效应”问题，提出一种波形延拓新方法——横纵向比例延拓法。在进行电压暂降的检测时，首先对原始信号进行提升小波降噪，然后对去噪信号进行横纵向比例延拓，继而对延拓后的信号进行LMD分解，将分解得到的乘积函数分量按原信号对应的时刻进行截取，得到改善端点效应后的分解结果，最后，从LMD分解后得到的瞬时幅值和瞬时频率提取电压暂降的特征信息。与希尔伯特一黄变换的检测结果进行了比较，结果表明所提出的电压暂降检测方法是可行、有效的，可为进一步进行电压暂降源扰动识别提供依据。A new approach for voltage sag detection and analysis using local mean decomposition （LMD） is proposed. The method uses instantaneous amplitude and instantaneous frequency obtained by the decomposition to detect the drop value, frequency and the starting and ending time of the voltage sag. A new method of waveform extension which names horizontal and vertical proportion extension method is proposed to improve the end effect of LMD. Firstly, the lifting wavelet is applied to denoise original signals and horizontal and vertical proportion extension is performed on the denoised signals. Then the extended signals are decomposed by LMD. Further, the product function given by the decomposition is intercepted according to the corresponding time of the original signals. Finally, the feature information of voltage sag is extracted form instantaneous amplitude and instantaneous frequency obtained by LMD. The test results are compared with the results of Hilbert-Huang transform （HHT）,and the simulation results illustrate that the proposed method is feasible and effective, which can provide a basis for the further identification of different voltage sag sources.

关 键 词：计量学 电压暂降 局部均值分解 横纵向比例延拓 端点效应 扰动检测 

分 类 号：TB971[一般工业技术—计量学]