Which motor is used in traction?
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. Thus, DC motors are perfectly suitable for traction.
Why DC series motor is used in traction drive?
DC Series motor has high rate of acceleration and retardation. DC Series motor is variable speed motor. Due to these characteristics motor is protected against overload. … DC series motor has develops high torque at low speeds, low torque at high speed, this is the basic requirement of traction unit.
Which motor is most suitable for 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 is it called a traction motor?
Before the mid-20th century, a single large motor was often used to drive multiple wheels through connecting rods. This was the same way that steam locomotives would turn their drive wheels. … This is called a “nose-suspended traction motor”.
Which DC motor is used in traction system?
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.
Which motor is used in DC system of traction?
Traditionally, these were series-wound brushed DC motors, usually running on approximately 600 volts. The availability of high-powered semiconductors (thyristors and the IGBT) has now made practical the use of much simpler, higher-reliability AC induction motors known as asynchronous traction motors.
Which DC motor is used in train?
Series-wound DC motors. That means current flows through the armature, then through the fields. They have high starting torque, favorable for starting a train. Nowadays the trend is toward AC motors, typically a 3-phase induction motordriven by a DC->AC inverter control.
Which traction system has high efficiency?
DC train consumes less energy compared to AC unit for operating same service conditions. The equipment in DC traction system is less costly, lighter and more efficient than AC traction system. It causes no electrical interference with nearby communication lines.
Which DC motor has self relieving property?
Which DC motor has got maximum self-relieving property? Explanation: DC series motor develops large starting torque initially and slow down with increase in load and so get automatically relived from heavy excessive load. Thus, DC series motor is called as self-reliving machine.
Why induction motor is used in traction?
This is the most important feature of traction motor provides opportunity for saving on energy but also smoothness in braking, saving on wear and tear in mechanical braking system. An Induction motor works as a generator if mechanical speed is more than the synchronous speed.
What is the work of traction motor?
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.
Are locomotives AC or DC?
Rectifier locomotives, which used AC power transmission and DC motors, were common, though DC commutators had problems both in starting and at low velocities. Today’s advanced electric locomotives use brushless three-phase AC induction motors.