高速列车高次谐波负荷建模方法

Modeling of high-order harmonic load for high speed train

为研究高速列车高次谐波负荷模拟方法,基于正弦切割数学模型分析了高速列车四象限变流器脉冲波产生的机理,理论推导出对应不同采样技术负荷电流高次谐波频谱计算公式,进而提出了一种新的高速列车高次谐波负荷建模方法。以CRH3为例,将时域仿真与现场试验得到的负荷电流数据进行傅里叶分解,得到的负荷电流谐波频谱分别与模型计算结果进行了对比,结果证明了所提负荷建模方法的正确性与精确性。进一步分析了四象限变流器多重化对负荷电流谐波频谱的影响以及非合理高次谐波产生的原因,以四重化四象限变流器为例,分别对正常工况与故障工况下负荷电流谐波频谱进行了计算与对比。

In order to research the simulation method of high-order harmonic load for the high speed train, the sinusoidal cutting mathematical model is used to describe the mechanism of pulse generation of four-quadrant converter and the formulas for computing the high-order harmonic spectrum of load currents corresponding to different sampling topologies are deduced in theory,based on which,a way to model the high order harmonic loads of high speed train is proposed. With CRH3 as an example,the load current data obtained by the time domain simulation and site experiment are processed by Fourier decomposition to get their high-order harmonic spectrums,which are compared respectively with those computed by the load model to verify the correctness and accuracy of the proposed modeling method. The influence of multifold four-quadrant converters on the harmonic frequency spectrum of load current is studied and the cause of unreasonable high order harmonics is analyzed. With harmonic spectrums of its load currents under normal four-fold four-quadrant converter as an example,the and fault conditions are calculated and compared.