摘要
本文首次将改进的Hilbert-Huang Transform(HHT)方法用于船舶电力系统谐波检测中。HHT方法在分析船舶电网谐波时存在模态混叠现象,不能有效得出各次谐波分量,本文采用基于Fourier变换的empirical mode decomposition(EMD)方法,根据Fourier谱进行频带滤波,然后再利用EMD分解得到准确的intrinsic mode function(IMF),最后进行Hilbert变换得到各次谐波分量的瞬时频率和瞬时幅值。有效解决了Fourier变换不具备时频局部特性以及HHT方法存在的模态混叠问题,实现了真正意义上的时频分析。在MATLAB/Simulink平台上建立船舶电网谐波源模型,仿真谐波电流信号,应用改进的HHT方法进行分析,并与小波包变换方法相比较,仿真结果表明改进的HHT对船舶电网谐波检测效果非常好。
Improved Hilbert-Huang Transform（HHT） is introduced for detection and analysis of power quality in marine power system for the first time in this paper.Mode mixing is happened when using EMD directly for harmonic analysis,and all harmonic components cannot be effectively separated.The HHT method based on Fourier transform is used to solve the problem in this paper.Firstly,signal is filtered according to Fourier spectral.Then,the output of signal after band filter is decomposed by EMD,and accurate IMF components are obtained.Lastly,Hilbert transform is used for the IMF components,and amplitude and frequency of corresponding time can be detected accurately and quantitatively.The HHT method based on Fourier transform can separately detect harmonic components and obtain the time-amplitude and time-frequency of harmonics.Simulation results show that this method has better performance in analyzing Harmonics to Wavelet packet in marine power system.
出处
《电工电能新技术》
CSCD
北大核心
2011年第3期10-14,共5页
Advanced Technology of Electrical Engineering and Energy
