Simulation Analysis of Dynamic Characteristic of Harmonics for High-Speed Locomotive Running at Rated Power

An analytical method for calculating the dynamic characteristic of the harmonics of high-speed locomotives running at a rated power was presented by analyzing the generation process of harmonic voltage and the characteristics of harmonic impedance of a traction power supply system.Based on the double Fourier series and the Bessel function,the expression of harmonic voltage of a PWM(pulse width modulation) rectifier was deduced.Based on the distributed parameter model the formula of calculating harmonic impedance for an overhead contact system was derived,and from the formula,series resonances and parallel resonances were analyzed.Frequency spectrum characteristics of harmonic voltage and harmonic current under the condition that a high-speed locomotive runs at a rated power were simulated and analyzed.The research results indicate that the frequency spectrum characteristics of both harmonic current and harmonic voltage vary,especially the former;series resonances occur at some frequency and the resonance position depends on locomotive position along the line;harmonic current contents are small,and the main contents are the 3rd to 9th and series resonance harmonics.