基于EEMD与小波阈值去噪的单相接地故障选线方法

Line selection method for one-phase grounding fault based on EEMD and wavelet threshold denoising

矿井供电系统发生单相接地故障时,由于井下环境恶劣,采集到的信号含有大量噪声,极易发生错选、漏选等问题。为此,文章提出了一种基于EEMD与小波阈值去噪的单相接地故障选线方法。该方法首先对采集到的零序电流信号进行EEMD分解,提取分解得到的高频IMF1分量进行小波阈值去噪,对去噪后的IMF1分量进行Hilbert变换并提取瞬时幅值,根据能量占比最大原则判断故障线路。通过RTDS实时数字仿真系统搭建了35/6kV的矿井供电系统仿真模型并进行故障仿真验证,结果表明该方法在不同故障条件下均具有较好的选线准确率与可靠性。

When single-phase grounding fault occurs in the mine power supply system,the collected signal contains a lot of noise because of the underground environment,it’s easy to cause the problem of wrong or missing selection.In order to improve those problems,this paper proposes a single-phase grounding fault line selection method based on EEMD and wavelet threshold denoising.Firstly,EEMD is used to decompose the collected zero sequence current signal.Secondly,the wavelet threshold denoising is used to extract the high frequency imf1 component.Thirdly,the rt transform is used to extract the instantane ousamplitude ofthe imf1 component after denoising.And finally,the fault Hilbelineis judged according to the principle of maximum energy proportion.A 35/6 kV simulation model of mine power supply system is built by RTDS real-time digital simulationsystem,the line selection method is verified by fault simulation.The result shows that this method has better aKccuracy and timeliness in different fault conditions.