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| New Detection Method Based on Local Mean Decomposition for Voltage Sags |
| HU Biao1,WANG Xiao-guang1,WU Su-min1,WU Li-na2 |
1. State Grid Zhejiang Yunhe Electric Power Company, Yunhe, Zhejiang 323600, China
2. North China Electric Power University, Baoding, Hebei 071003, China |
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Abstract 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.
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Received: 12 June 2014
Published: 20 October 2015
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| About author:: 胡标（1967-）,男,浙江龙泉人,国网浙江云和县供电公司工程师,研究方向为供电公司生产管理。wsmer@163.com |
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2015, Vol. 36 
