Research Of High-speed Railway Traction Power Supply Quality

Since Aug.1,2008, China's first speed of 350km Beijing-Tianjin intercity high-speed rail operations, indicates that China's high-speed rail technology have advanced into the ranks of the world, and opens the prelude to the great development of railway. High-speed railway traction power supply system is one of the important sub-system, traction power supply quality is an important guarantee for high-speed railway traction power supply system to work.Firstly, the paper presents the equivalent circuit of traction substation and sectioning post, connecting different power arms. A general mathematical model suitable to traction power networks fed by different power supply modes is established. Parameter identification method is used to establish a model of induction motor paralleling static part of train's traction and drive system, full account of the train and traction grid interaction, leading to a more realistic reflection of the trend of the distribution of traction power supply system.Secondly, according to CRH type EMU traction drive principle, the use of Matlab/Simulink to build CRH3/CRH2 electromagnetic transient model, and the traction equation of electromechanical transient interact, the method can not only reflect the electromechanical transient in traction network, but also the dynamic characteristics of motors. The amount of electromagnetic models distributed to different computing notes by parallel technology, in order to reduce calculation time and improve computational efficiency.Then, from the top goal-setting high-speed rail design, this paper proposes the optimization of traction power supply system design process. Based on the traction multi-conductor transmission line model, according to Ampere-Kilometer traction curve, traction minimum power loss model is derived, and use the PSO algorithm to design of the traction substation and section post location, by finding a reasonable distance of the traction power supply, making traction power loss minimum. On this basis, according to the optimum design of traction current, calculation the traction transformer capacity under a variety of wiring, considering the traction transformer capacity, equipemnt utilization and other factors, to select a suitable traction transformer wiring and installation capacity. And comprehensive comparison of the ground automatic convert method and the onboard automatic convert method, to save travel time and energy and environmental point of view to choose the right neutral-section passing approach.Lastly, from the introduction of the three-phase power system fundamental and harmonic model starting to introduce the vector method for solving three-phase power system fundamental current and harmonic current approach, combined with high-speed railway traction power supply system is proposed traction power supply system-public power flow calculation method of coupling, analysis of high-speed railway traction power supply system for power systems, including power system bus voltage phase imbalance, traction harmonic current, harmonic voltage distribution grid, and the results with the national standard for comparison.