What is 2 25 kV traction system?
What is 2 25 kV traction system?
2×25 kv AT system is a kind of power supply system in AC 25 kv 50 Hz single phase traction. It has a feeder wire located along the track and Auto Transformers installed every 10 to 20 km . Traction load is supplied by 25 kv from both adjacent ATs through the contact wire and rail same as the conventional system.
What is the capacity of traction transformer?
Traction transformers usually have the following overload capacity : 1. Overload rating: (a) 50% overload for 15 min., and (b) 100% overload for a period of 5 min.; after the transformer has attained steady temperature on continuous operation at full load.
What is the voltage of traction?
Standardized traction voltages are 750 V DC, 1500 V DC and 3000 V DC. The three-phase voltage from the local utility is stepped down and rectified in the traction substations to provide the required DC voltage.
Why is 25 kV used in electric traction?
The main reason for 25kV voltage used in railway is, that 25 kV AC more economical than 1.5kV DC voltage system. Since 25kV voltage system has higher voltage, the higher voltage reduces the current flow through conductor; this reflects to reduce the conductor size. The cost of the conductor gets less.
What is 25 kV Catenary protection?
The 25 kV supply for traction system is drawn through a single phase step down transformer. This is modeled as a 25 MVA, 220 kV/25kV, two winding single phase transformer with impedance of 12% at 25 MVA base. The average length of the catenary to be protected during normal feed conditions is 40 km.
What is SSP in railway?
Sub-Sectioning and Paralleling Post (SSP)
Which transformer is used in electric traction?
Hitachi Energy’s traction transformers are integral to this capability. Their function is to transfer electric power from the catenary to the motor by lowering the network’s high voltage to low voltage for use by the converters.
Which type of transformer is used in railway?
Catenary autotransformers are used in modern high-power railway catenary systems fed with two phases with a 180° phase shift, with the mid-point connected to the earth.
Which motor is used in traction system?
4.6
| Motor | Application |
|---|---|
| DC series motor | Traction system, Cranes, air compressors |
| DC shunt motor | Lathe Machines, Centrifugal Pumps, Blowers, Conveyors, Weaving Machine, Spinning machines |
| DC compounded motor | Presses, Shears, Elevators, Rolling Mills |
| Stepper motor | 3D printing equipment, Small robotics, CNC milling machines |
What is high-voltage traction?
The high-voltage inverter converts direct current (DC) from the batteries or generator to alternating current (AC) to power the traction drive motors.
Why do we use 50hz supply in electrical traction system?
The high-voltage distribution system at 50 Hz supply is converted to this electric motor rating by transformers and frequency converters. This system employs two overhead lines, and the track rail forms another phase, but this raises many problems at crossings and junctions. Advantages; Fewer substations are required.
