基于改进Hilbert-Huang变换算法的电气化铁路谐波检测

通过对电力机车负载电流进行仿真建模,得到电力机车在不同工况下的电流波形;使用改进的Hilbert-Huang变换算法对电流波形进行谐波检测;采用限制带宽经验模态分解算法对原始电流波形进行分解;通过引入屏蔽信号来控制本征模态函数的带宽,以有效抑制模态混叠.结果表明,所提出的改进Hilbert-Huang变换算法能够有效检测电气化铁路负载电流中各次谐波随时间变化的特征.

Harmonic Detection of Electrified Railway Based on Improved Hilbert Huang Transform Method

Electrified railway is one of the major harmonic sources in the power system, which is greatly affected by the route and weather. So, precise detection of electrified railway power load harmonic is of great important for the safety of power grid. A math mode of electric locomotive was built in this paper, from which the load current of the railway under different conditions was acquired. An improved Hilbert Huang transform was applied to extract the harmonic of the current waveform in which bandwidth restricted empirical mode decomposition (EMD) method was used. By adding masking signal, the mode mixing could be restrained effectively. The simulation results show that the proposed method can extract the time-frequency distribution of the harmonics in electrified railway, which provides a new method for harmonic detection of electrified railway.