摘要
针对传统的谐波检测算法无法分析牵引供电系统中的非线性、非平稳谐波的问题,文章提出一种基于改进自适应噪声的完整集合经验模态分解(ICEEMDAN)与Teager能量算子(TEO)相结合的谐波检测算法。其先将待测信号经ICEEMDAN得到一组固有模态函数(IMF)分量,再通过筛除虚假分量,得到真实的IMF分量;然后,对各个IMF分量进行Teager能量算子(TEO)解调,得到谐波分量的幅值与频率随时间变化的图像。经分析得出,ICEEMDAN作为希尔伯特-黄变换(HHT)中的重要步骤经验模态分解(EMD)的改进算法,相较EMD的其他改进算法,其抑制模态混叠的效果最佳,并具有良好的自适应性,在处理非线性非平稳信号时有着很好的表现;而TEO能准确检测出谐波的瞬时幅值与频率,并快速响应信号的变化。通过构造牵引网特性中的谐波信号对该算法进行仿真分析,结果显示,分析稳态电流谐波时,幅值与频率的平均检测误差分别为3.56%和1.74%;分析暂态电流谐波时,幅值与频率的平均检测误差分别为3.39%和2.44%。这表明文章所提算法能够对牵引供电系统谐波的幅值与频率进行准确的检测,并可以准确定位谐波信号的突变点。
In view that the conventional harmonic detection algorithms cannot support analysis on nonlinear and non-stationary harmonics in the traction power supply systems,this paper proposes a harmonic detection algorithm based on the improved complete ensemble empirical mode decomposition with adaptive noise(ICEEMDAN)and Teager energy operator(TEO).The first step is to process the signal to be detected into a set of intrinsic mode function(IMF)components through ICEEMDAN,and then obtain the true IMF components by filtering out the false ones.Then,performing TEO demodulation on each IMF component can generate the variation charts of amplitude and frequency of harmonic components over time.It is revealed through analysis that ICEEMDAN,as an improved algorithm for empirical mode decomposition(EMD),an important step in the Hilbert-Huang transform(HHT),has the best effect in suppressing mode aliasing,compared with other improved algorithms of EMD.Thanks to its good adaptability,it also has good performance in processing nonlinear and non-stationary signals.On the other hand,TEO can accurately detect the instantaneous amplitude and frequency of harmonics,and quickly respond to signal changes.The proposed algorithm was simulated and analyzed by constructing harmonic signals of the traction network characteristics.The results show that the average detection errors of amplitude and frequency were 3.56% and 1.74% respectively when analyzing steady-state current harmonics,and 3.39% and 2.44% respectively when analyzing transient current harmonics.This indicates that the algorithm proposed in this paper can accurately detect the amplitude and frequency of harmonics in the traction power supply systems,and can accurately locate harmonic signal singularity.
作者
谢泽恩
XIE Zeen(China Railway Siyuan Survey and Design Group Co.,Ltd.,Wuhan,Hubei 430000,China)
出处
《控制与信息技术》
2023年第3期52-61,共10页
CONTROL AND INFORMATION TECHNOLOGY
