Study On Key Technology Of The New Traction Power Supply System

With the development of China's economy,the requirements for railway transportation are getting higher and higher.As an important part of the electrified railway,the traction power supply system naturally needs continuous development and progress.The proposal of co-phase power supply technology provides a good solution for solving the problem of train over-phase and power quality.With the development of co-phase power supply technology and continuous engineering application,its application to electrified railway is accelerating.At the same time,with the study of urban rail transit using AC system,urban rail transit and trunk railway unified system power supply has become a possibility.According to the new traction power supply system proposed by Professor Li Qunzhan,the traction power supply network and its connection mode and core technology in the new traction power supply system are introduced.Comparing the overhead power supply line and the power cable,the proposal for selecting the power cable is proposed for the material selection of the power supply network in the system.The flexible contact net,the rigid contact net and the newly proposed contact strip are compared in terms of equivalent impedance and current carrying capacity,and the conclusion that the contact strip is used for the new traction power supply system is superior to other contact power supply forms.At the same time,based on the structure of the new traction power supply system,the calculation method and current distribution of the voltage loss of the line are analyzed.A calculation method for calculating the voltage loss of the traction network without neglecting the angle between the head end and the end voltage vector is proposed.The calculation method of the current distribution of the two-layer power supply network in the new traction power supply system is given.Based on the corresponding standards and theories,from the aspects of 1)traction converter manufacturing,2)electrical insulation,3)power supply capability,etc.,the voltage level selection of the two-layer power supply network in the new traction power supply system is proposed.Finally,the model of the new traction power supply system is established according to the Matlab/Simulink simulation platform.The theoretical derivation of voltage loss and current distribution is simulated and verified.The no-load voltage of the new traction power supply system and the voltage distribution of the traction network during compact operation are analyzed.