Power quality analysis of traction supply systems with high speed train

The characteristic of harmonic currents of high speed train is significantly different from DC-drived locomotives. The rectifier of CRH5 electric multiple units (EMUs) in China is researched in this paper.The principle of four-quadrant converter and its predictive current control strategy are studied. The formula of fundamental and harmonic currents of the parallel two-level four-quadrant converter is given under different power and grid voltage based on double Fourier transform method. Therefore the distribution characteristics of harmonic currents are analyzed. The simulation software based on Matlab/Simulink is developed for harmonic analysis of CRH5 EMUs. With different traction power, braking power and traction grid voltage, the harmonic currents of EMUs injecting to the traction grid are studied and compared.