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Which part is available in slip ring induction motor ?
Frame
Stator
Slip ring
All of above
All of above
A slip ring induction motor (also known as a wound rotor induction motor) consists of a stationary stator and a rotating rotor. The rotor windings are connected to external slip rings, which are further connected to external resistors for speed control and starting torque enhancement, making all listed components essential parts of the machine.
A slip ring induction motor (also known as a wound rotor induction motor) consists of a stationary stator and a rotating rotor. The rotor windings are connected to external slip rings, which are further connected to external resistors for speed control and starting torque enhancement, making all listed components essential parts of the machine.
TstтАЛтИЭR2тАЛ┬░2+X2тАЛ┬░2R2тАЛтАЛ тАФ Relationship showing how rotor resistance R2тАЛ impacts starting torque
s=NsтАЛNsтАЛтИТNrтАЛтАЛ тАФ Slip equation for induction motors
The stator carries a three-phase winding that creates a rotating magnetic field when energized. This magnetic field induces an EMF in the rotor windings, which are connected to slip rings and external resistors. By varying the external resistance via these slip rings, the motor's starting torque is significantly increased and its speed can be controlled during operation.
Slip rings allow the connection of external resistances to the rotor circuit.
Wound rotors are used in applications requiring high starting torque.
The stator provides the rotating magnetic field.
The frame provides mechanical support and protection for the stator core.
High starting torque
Variable speed control capability
Reduced starting current
Higher maintenance due to brushes and slip rings
Lower efficiency compared to squirrel cage motors
Higher initial cost
Cranes and hoists
Elevators
Compressors requiring high starting load
| Feature | Slip Ring | Squirrel Cage |
|---|---|---|
Starting Torque | High | Low |
The slip rings are mounted on the rotor shaft and insulated from it.
External resistance is gradually cut out as the motor gains speed.
D is correct тАФ The frame, stator, and slip rings are all fundamental components required for the construction and operation of a slip ring induction motor.
Always remember that slip ring motors are specifically chosen when starting torque is the primary design constraint over simple maintenance requirements.