Composition of electric traction power supply system
The electric traction power supply system refers to the electric energy received from the electric power system or the primary power supply system, through the transformation, phase change or commutation, to provide the electric power of the electric locomotive load with the required current system, and complete all functions of traction power transmission, power distribution, etc. Complete system is mainly composed of a traction substation and a traction network. The single-phase power supply of the traction network is composed of feeders, contact networks, track circuits and return lines. In order to make electrical energy supply to electric locomotives efficiently and reliably, the traction network is also equipped with equipment such as phase isolator and isolator, and the power supply system also includes switchgears and partitions. my country stipulates that the rated voltage of the traction network is 25kV and the rated frequency is 50Hz. The loops of traction power supply are: traction substation-feeder-electric locomotive-rail and earth-return line-traction substation.
Traction substation is an important part of AC power frequency single-phase electric traction power supply and transformation system. Its function is to convert the 110kV or 220kV three-phase AC power introduced into the power system into 27.5kV or (2×27.5) kV single-phase AC power, and send it to the contact network on the railway line through the feeder line, which is used by the power locomotive. A few traction substations are also responsible for supplying 10kV power loads to industrial and agricultural users in railway areas. Therefore, the traction substation is a hub that receives and distributes electrical energy and changes the voltage of the electrical energy. It is an important link between the power system and the electric locomotive. It is mainly composed of a traction transformer and corresponding power distribution device.
Overhead contact net is a chain-type cargo wire system suspended above the electrified railway rail and keeping a certain distance from the rail surface. It is a special point circuit designed to provide power for electric locomotives or electric trains. The locomotive contacts with the pantograph Net East China contacted to obtain electrical energy.