Study On Electrical Coupling Characteristics Of Train Traction Network Of Electrified Railway

Traction power supply system and power train constitute train-network coupling system,good matching relationship of train-network coupling system is the key to ensure the traction power supply system power quality and safety,stability,continuous operation of electric trains.During the operation of electric train,the train-network coupling system appears a variety of complex abnormal electrical processes due to electrical mismatch,which seriously affecting the reliability and security of traction power supply system and operating trains.Two abnormal electrical processes about traction network voltage oscillation phenomenon,and the inrush current and sympathetic inrush phenomenon of electric trains were studied which exist in train-traction network coupling system,and the improvement schemes were proposed.The main research contents and achievements are as follows:The traction network voltage oscillation generation mechanism of the train-traction network coupling system was analyzed.A train-traction network coupling system model considering the parameters of traction power supply system and the control parameters of electric trains was established.Through the frequency domain analysis of the equivalent model of the train-traction network coupling system,the closed-loop transfer function of the system was established,and the key factors affecting the stability of the system were analyzed.The voltage oscillation of the traction network was reproduced by time domain simulation,and the influencing factors were simulated and verified.The influence of inrush current on the train-traction network coupling system was analyzed.The equivalent circuit model and the simulation model of traction power supply system when the train transformer closed were built.A joint simulation model of traction network distribution parameter model,power train transformer and electric locomotive converter was also established.The generation mechanism of inrush current of electric locomotive transformer and sympathetic current of operating locomotive transformer is studied,and the key factors influencing inrush current are analyzed.The influence of inrush current of electric Locomotive transformer on the system was analyzed.The dq decoupling control strategy was proposed for electric locomotive converter.Through the control of reactive current,the voltage oscillation of traction network was suppressed.A new automatic passing neutral section scheme was proposed.The structure and working principle were introduced,and the simulation of the process of the train with continuous electric current passing through the neutral section was analyzed.