The Research On DC3000V Traction Power Supply Scheme Of Urban Rail Transit

With the rapid development of city rail traffic which is increasingly important in people's daily life,depends on a more safety and reliable rail system that has a high power capacity.In order to promote the further development of rail system,we should pay attention to these aspects.During the research of urban rail transit power supply system,there are some existing problems which have some negative impacts on the system.In order to raise the efficiency and benefit of rail system,a new traction power supply system for urban rail transit is presented in this paper.The proposed scheme increase the voltage level to DC3000V based on the existing DC 1500V power supply system to solve the problems,such as urban rail transit stray current,rail potential and electromagnetic interference.In this paper,the following research is mainly carried out on the neutral point grounding system of the positive and negative rail power supply:First of all,after researching on the phase shift transformer,this paper puts forward the transformer secondary side two fault connected phase-shifting technique,and deduces the formula of the phase angle,and the relationship between voltage and turns ratio,based on one side of the extend triangle phase-shifting method;secondly,for the sake of verifying the feasibility of the system,the simulation model of traction rectifier unit is constructed to make the comparative research on the positive and the negative rail current neutral grounding power supply and the existing system of urban rail transit power supply system;thirdly,according to the earth orbit parameters,this paper simulates the three rail system of stray current and rail potential with the positive and negative system of those by establishing a system model;after that,through constant magnetic field theory,this paper analyzes if the same side or opposite side installation condition of three rail system would affect electromagnetic field around the system diversely,and later,simulates the theoretic results;Finally,this paper researches the vehicle main circuit and proposes reforming scheme of two group of vehicle main circuit based on the existing of positive and negative power rail system.