Research On High-Voltage DC Traction Power Supply System

With the rapid development of high-speed railway, an increasing number of problems arose in the existing traction power supply system, and have become a bottleneck in the development of high-speed railway. High-voltage DC traction power supply system could solve these problems effectively, and has become one research direction for the future railway development in China. Determining the voltage level is a very important aspect of high-pressure studies of DC traction power supply system. In this thesis, detailed analysis and discussions have been carried out in many aspects.After simple introduction of All-Parallel AT Power Supply system, 3 schemes about how to determine the voltage of high-voltage DC traction power supply system were put forward, then the structure of the form of trolley line at different levels of DC voltage was established. Finally, on the basis of Beijing-Tianjin High-speed railway, supply arm length and power loss of the trolley line were calculated under the same transportation.Stray current has a serious corrosive effect on the underground metal structure, which may cause serious consequences. Reducing the stray current is an effective method to prevent accident. In this thesis, the mathematical analysis have been carried out on the basis of stray current model of bilateral power supply system, and the relationship between the train current and stray current was analyzed by method of computer simulation. Finally, the conclusion that increasing voltage could reduce the stray current effectively was drawn.Hoop pantograph and trolley line have very special characteristics of working conditions, current plays a vital role in electrical contacts of this pair of friction. This thesis analyzed the influence of the current size to the thermal effect of contact resistance and off-line arc energy, and demonstrated that the double-pantograph could help reduce electric corrosion in two aspects: the temperature raise of contact resistance and arc corrosion.These 3 schemes about how to determine the Voltage of high-voltage DC traction power supply system are analyzed and compared in many respects. And the conclusion that the voltage of high-voltage DC traction power supply system is 35kV was reached. At the same time by comparing of high-voltage DC traction power supply system and All-Parallel AT Power Supply system, this thesis draw a conclusion that the former had the advantages of the economic and technical.