基于希尔伯特-黄变换的飞机供电系统谐波信号分析

摘要

大量非线性电力设备的应用，使飞机供电系统中含有大量的谐波分量和间谐波分量。针对傅里叶变换和小波变换等方法不能有效地对这些谐波信号进行提取和分析的情况，提出利用希尔伯特-黄变换(HHT)提取和分析飞机供电系统中的各次谐波分量。同时，为了改善HHT中经验模态分解(EMD)存在的包络线过冲、欠冲和端点飞翼等问题，使用分段三次埃尔米特多项式插值代替三次样条插值提取包络线，使用半周期半对称延拓法扩展信号边界。仿真结果表明：改进后的希尔伯特-黄变换可以更有效地提取和分析飞机供电系统中的各次谐波分量。%Because of the application of the non - linear electrical equipment, aircraft power system contains a number of harmonic components and inter - harmonics components. Aiming at the situation that the Fourier transform and wavelet transform method can not effectively carry out these harmonic signal extraction and analysis, the paper made use of Hilbert - Huang Transform ( HHT) extraction and analysis of the harmonics component for aircraft power system. Meanwhile, in order to solve the questions of overshoots,undershoots and the end swings existing during empirical mode decomposition (EMD) , it made use of cubic hermite polynomial interpolation for envelopes fitting instead of cubic spline interpolation extraction the envelope curve and the advantages of semi - periodical - semi - symmetrical method extending the signal boundary. The result of simulation shows that Hilbert - Huang transform can effectively extract and analyze harmonic component for aircraft power system.