How traction motor works in locomotive?

The motors used are induction or asynchronous motors designed to have characteristics suitable for traction. The speed and torque of the motor are controlled by varying the frequency, voltage and current applied to the stator coils. Motors for a typical locomotive would be in the range 400 to 600 kW.

What is traction motor in locomotive?

Traction motors are powered by electricity and generate the power to rotate the wheels of the train. The turning force produced by traction motors is transmitted to the wheels via the driving gear unit and axle. Traction motors are typically mounted in the trucks where the wheels are housed.

What is the motor used in locomotives?

DC motors are used on trains is because of their high torque and good speed control. Compared to AC motors, DC motors can provide industry applications with a fine balance of strong starting torque and controllable speed for seamless yet precise performance.

How does a locomotive get traction?

Trains get traction because of the immense weight of the locomotives, and the friction generated between the wheel and rail head. Furthermore, in less than ideal weather conditions, sand is sprayed on the rail head to reduce wheel slip.

Which motor is more suitable for traction service?

DC Series motor speed-torque characteristics are such that as torque increases speed decreases. DC series motor has develops high torque at low speeds, low torque at high speed, this is the basic requirement of traction unit. Commutating property of series motor is good so we get sparkles commutation.

Are locomotives AC or DC?

All in all, the AC traction locomotive offers about twice the amount of adhesion as a DC unit. Therefore, a modern lightweight AC locomotive such as the RX500 can provide as much or more tractive effort than an old style DC unit like the SW1200 which weighs 60% more.

What is the function of traction motor?

A traction motor is used to make rotation torque on a machine. It is usually changed into a straight line motion. Traction motors are used in electrically powered rail vehicles such as electric multiple units and electric locomotives.

Which motor is most suitable for electric traction?

Many single phase ac motors have been developed for traction purposes but only compensated series type commutator motor is found to be best suited for traction. Single phase induction motors have been abandoned as they are not capable of developing high starting torque.

Why train engines are not turned off?

Another reason for not turning off diesel train engines, lies in the engine itself. It is also interesting to know that while diesel locomotives are idling, fuel consumption is more than when the train is moving. This is because, while idling, the batteries are being charged, and the air compression is in operation.

Why do train wheels not slip?

The causes of locomotive wheelslip vary, but the predominant factor lies in the power-to-weight ratios. However, if the power of a locomotive vastly exceeds its weight, then an imbalance ensues which causes the violent spinning of the wheels through loss of traction.

What are the requirements of traction motor?

General requirements of Traction motors / traction system

• High starting torque. A traction motor must have high starting torque.
• Simple speed control –
• Suitable speed Torque Characteristics –
• Parallel Running –
• Overload Capacity –
• Size of Motor –
• high Efficiency.
• Braking –

Which motor is preferred the most for traction purpose Why?

Why are the DC motors preferred for traction applications? Explanation: DC motors are used for traction as, according to the characteristics of DC motors speed is inversely proportional to torque and square of armature current as well, if linear magnetization is concerned.

How does a traction motor work in a locomotive?

At start up the maximum current flows through the motor, providing maximum torque. As the motor speeds up, back-EMF reduces the current and the torque, and series resistance is switched out step-by-step to maintain the required torque until full speed is attained. Resistance switching gives a step-type change in torque, and hence acceleration.

What kind of power does a diesel locomotive use?

This article covers the diesel locomotive. The name “diesel locomotive” is misleading, as the traction power is provided by electric motors driving the wheels directly, and the electricity to power the motors is generated by an alternator driven by a diesel engine.

Can a traction motor be mounted on the wheel?

Mounting a traction motor directly on the wheel has been a goal since electric motors were first used in locomotives. PMSMs with high specific torque are likely to make this possible in the future. Prototype models have been developed successfully.

What kind of frequency does a traction motor use?

2⁄3 Hz frequency used for AC traction motors. The AC system allows efficient distribution of power down the length of a rail line, and also permits speed control with switchgear on the vehicle.