An induction motor fed from rotor is a type of motor in which the power is supplied to the rotor instead of the stator. This type of motor is also known as a wound rotor induction motor.
In this type of motor, the stator windings are connected to the power supply while the rotor windings are connected to a set of slip rings. The power is then transferred from the stator to the rotor through the slip rings. The rotor windings act as a secondary winding, inducing a magnetic field that interacts with the stator's magnetic field to produce rotation.
One advantage is that it allows for speed control by varying the resistance in the rotor windings. This type of motor also has a higher starting torque and lower starting current compared to a squirrel cage induction motor. Additionally, it can handle high overload conditions without overheating.
This type of motor is commonly used in applications that require variable speed control, such as cranes, hoists, and elevators. It is also used in industries where high starting torque is needed, such as in the mining industry.
Maintenance and repair of this type of motor are similar to that of a squirrel cage induction motor. However, in addition to the stator, the rotor also needs to be inspected for any damage or wear on the slip rings and brushes. These components may need to be replaced periodically to ensure proper functioning of the motor.