A traction transformer is an electrical device used in the design and manufacturing of the railway system for transferring the energy by electromagnetic induction from one circuit to another. It replaced the fossil-fuel traction system years ago and now functions as an integral part of the electric traction system.

Traction transformer converts electricity supplied by the power company into a suitable voltage for driving the motors and other auxiliary devices such as illumination, heating and air circulation, information to passengers, braking, and communication.

It basically alters high voltage AC to low voltage DC fed into the DC motor rectifier. Additionally, the traction transformer output can be fed to the rectifier-inverter set for three-phase AC traction motors.

The main part of the rolling stock is the traction transformer. In the past, transformers were commonly used for rail traction and regarded as the most effective alternative to conventional traction systems for fossil fuels. It is one of the key components of the electric traction system in the vehicle nowadays, and it contributes to the smooth movement of motors used in locomotives, high-speed trains, and trams.

In the manufacturing of traction transformers, raw materials such as transformer steel and high-grade copper are widely used. It generally takes up a lot of space and weight, leading to increased load on the train axle and the need for extra energy. The transformer is mounted on the roof or floor or in the train’s machine room, depending on the size and stage of the device such as single or multi-phase.