基于CEEMD能量比重谐振接地系统故障选线方法

Fault Line-Selection Method in Resonant Grounded System based on CEEMD Energy Proportion

本文利用补充的总体平均经验模态分解(CEEMD)方法对零序电流进行分解,得到固有模态函数(IMF)分量以及剩余分量,CEEMD在克服模态混叠的同时,有效的中和了添加的白噪声,使分解更具有完备性。在此基础上将IMF分量所对应的频带能量,同时将IMF分量与原零序电流进行相关性分析得到相关系数,然后把相关系数作为权重系数赋予到频带能量中,将经过加权后的频带能量累加得到每条线路的能量,进行归一化得到能量比重形成选线判据。在Matlab/Simulink上搭建线缆混合配电网模型进行仿真,结果表明,该方法受故障合闸角,故障距离,过渡电阻等影响小,方法简单,一定程度上提高了选线准确性。

This paper used complementary ensemble empirical mode decomposition(CEEMD) to extractintrinsic mode function(IMF) and remaining component of zero sequence current. CEEMD not only overcame the modal aliasing,but also could effectively neutralize the added white noise. So, it made the decomposition more completeness. On the basis of it, the frequency band energy which correspondedwith IMF was calculated, while using correlation analysis to get the correlation coefficientbetween IMF and zero sequence current. Then, correlation coefficient was used as weight coefficients for givingit to the frequency band energy. Furthermore, the weighted frequency band energy was accumulated as the energy of each line. Eventually, the energy of each line have been normalized as energy proportion to form a line selection criterion. At last, a distribution network simulation model with hybrid transmission lines was set up by Matlab/Simulink. The results showed thatthis method could select the fault line regardless of fault close initial angles, fault location, transition resistanceand etc. To some extent, this methodimprove the precision of afault line-selection.