An Induction Motor is consist of two main parts which as follows –
The stationary frame called ‘stator’ and rotary part is called as ‘rotor’. The figure shown that construction of induction motor.
The function of stator winding is to be produce a rotating magnetic field (RMF) in air gap between the stator and rotor.
The rotor is not connected to any external supply. The current flows through the rotor due to the principle of induction. Hence the induction motor.
Classification of induction motor
Following are the types of induction motor with compare between squirrel cage rotor and wound or slip cage rotor.
1. squirrel cage induction motor
2. wound or slip cage induction motor
|Squirrel cage rotor
||Wound or slip cage rotor
|This rotor is in the form of bars which are shorted at the end with the help of end rings.
||This rotor is in the form of 3 phase winding.
|In squirrel cage rotor no slip rings or brushes.
||In wound or slip rotor slip rings and brushes are used.
|It has a simple construction.
||It has complicated construction.
|External resistance cannot be connected.
||It is possible to connect external resistance.
|It has less rotor copper loss.
||It has high rotor copper loss.
|In squirrel cage rotor resistance starter cannot be used.
||In slip cage rotor resistance starter can be used.
Used in fans, water, pump etc.
It include in crane, elevators, compressors, lifts etc.