摘要
为解决谐振接地系统故障选线不准确和不实用的问题,提出了一种基于改进经验模态分解(EMD)与关联维数相结合的选线方法。采用改进的镜像延拓方法对传统EMD进行改进。将改进EMD方法应用于零序电流分析中,对分解得到的本征模态函数(IMF)中高频分量占比较高的前3个相加作为对应线路的特征频段。使用自相关法和改进的Cao法确定各线路特征频段的时间延迟参数和最佳嵌入维数,接着采用G-P算法进一步计算各线路特征频段的关联维数,利用故障线路和健全线路关联维数之间的大小差异进行故障选线。最后,仿真实验验证了所提方法的准确性和实用性。
In order to solve the problem of inaccuracy and impracticality of fault line selection in resonant grounding system,a method based on improved empirical mode decomposition(EMD)and correlation dimension is proposed.The improved mirror extension method is used to improve the traditional EMD.The improved EMD method is applied to the analysis of zero sequence current,and the first three high frequency components of the decomposed intrinsic mode function(IMF)are added as the characteristic frequency bands of the corresponding lines.The time-delay parameters and best embedding dimension of each line characteristic frequency band are determined by using autocorrelation method and improved Cao method.Then the correlation dimension of each line characteristic frequency band is further calculated by using G-P algorithm,and the fault line selection is carried out by using the difference of correlation dimension between fault line and sound line.Both simulation and experiment show the accuracy and practicability of the proposed method.
作者
范津玮
刘晓波
袁旭峰
黄元行
叶琦
熊焱
FAN Jinwei;LIU Xiaobo;YUAN Xufeng;HUANG Yuanxing;YE Qi;XIONG Yan(The Electrical Engineering College,Guizhou University,Guiyang 550000,China)
出处
《电力科学与工程》
2021年第6期53-61,共9页
Electric Power Science and Engineering
基金
国家自然科学基金(51667007)。
关键词
谐振接地系统
故障选线
改进EMD
关联维数
改进的Cao法
resonant grounding system
fault line selection
improved EMD
correlation dimension
improved Cao method
