The Harmonic Characteristic Research Of Locomotive And Traction Network For High-Speed Railway

With the High-speed Railway has been built and applied in China massively, the problems of electrical matching between widely used of AC-DC-AC locomotives and traction network become more and more prominent. What’s subject of the research in this paper are High-speed Railway AT power supply mode and CRH2motor train unit which were widely used in our country. Through the establishment of the model of locomotives and catenary combined system, the author analyze the distribution characteristics of the locomotive harmonic, and study the rules of harmonic resonance under locomotives and catenary system, then put forward the rational suppression scheme of harmonic resonance.According to the structure characteristics of AC-DC-AC locomotives traction drive system and on bases of the work principle and generation mechanism of harmonic of traction converters, the dynamic corresponding relationship between locomotive harmonic current of line side and power is analyzed. Combining with simulation results and the measured data, the distribution characteristics of the locomotive harmonic current is analyzed, and the locomotive harmonic model based on the measured data is established.The structure characteristics of the traction network in AT power supply mode which is widely used in High-speed Railway is analyzed, the theories of multi conductor transmission line and classical Carson are used to establish the multi conductor equivalent π model of traction power network. The traction power network is naturally divided according to the longitudinal connection element of traction network and the location of the locomotive, and then the multi-conductor chain network model of traction network is established.Based on the impedance characteristics of locomotive in traction power supply system, the idea to establish locomotives and catenary combined system is provided. According to the locomotive harmonic characteristic, the transmission characteristics and distribution regularities of locomotive harmonic current in traction power network is studied. The power quality problems may caused by locomotive harmonic current in the process of transmission on traction substation side and power system side are simulation analyzed. Based on the characteristics of the AT traction power network structure parameters, the simulation analysis of the system resonant characteristics under the change of traction network length, external power supply capacity, locomotive position, locomotive load power, AT leakage reactance and locomotive number. At the same time, combined with the new promoted power supply scheme of traction network subsection, analyzed the system harmonic resonant characteristics of all parallel AT traction network which under abnormal operation.Combined with the current strategy of settings passive filter in the end of the traction network to restrain high harmonic resonance, the simulation verified the effectiveness of harmonic suppression scheme based on second order damping filter and wavelet high-pass filter newly proposed. Comparative analyzed the inhibition effect of this two kinds of inhibition technology, compared the advantages and disadvantages of this two kinds of filtering scheme, and provided guidance for the engineering application of harmonic suppression scheme.