What is the difference between squirrel cage and slip ring induction motor?

Answer 1

the difference is that squirl cage the rotor is short circuited while it is on operation and out of operation while the rotor of the bother one is connected to nexternal circuit to reduce the starting intial current

Answer 2

Induction machines are AC-AC machines

ie the stator and the rotor must have AC sources supplied to them. Unlike a syncronous machine that is AC-DC or DC-AC (ie "AC stator DC rotor" or DC stator AC rotor"

The stator is stationary (unless you get special insideout machines). Due to the stator being stationary you can just plug in the stator windings into the utility supply (or via an inverter).

The rotor however is "rotation" thus there exist the problem of "energising" the rotors magnetic field. If you just provided wires to the rotor they would get twisted up.

By providing "slip-ring" you now have a means that electrical power can be suppled to a rotating connector. Thus teh slip-rings are on the rotor. There are machines out there that use Mercury for the brushes but they are specialist machines

As to squirrel-cage if you look at the rotor it looks like a cage. Again a squirrel-cage machine needs to establish a magnetic field on the rotor (so that it can be dragged round by the field on the stator)

How a squirrel-cage developes its rotor field is by the induced voltage that is generated by the stator field. The squirrel cage is made from two rings at the front and the rear of the rotor. A different voltage potential is developed in each ring (due to the stator). The squirrel-cage also has shorting bars linking the two rings (these bars are what makes the rotor look like a squirrel cage). These shorting bars "short" the induced voltage and current flows generating the rotors field.

Think of induction machines like Transformers -essentially that is what it is, its secondary winding is just rotating

Hope this helps.

Answer 3

The difference is in the rotor. For Squirrel cage, the rotor consist of slated laminate aluminium/fabricated bars. The end are then connected using conductive rings forming a cage like for a squirrel. For Wound Rotor, the winding consist of coils wound in slots which are then connected in series or series parallel forming a winding. Hence,wound rotor.

Answer 4

the main differences btwn slip ring i/m and squirrel cage I/M are:

1. SQ I/M rotor has cu bars inserted between the slots provided on core where as in case of slip ring I/M the slots on the core are filled with rotor windings.

2. the starting torque of slip ring I/m can be changed or increased by changing external resistance connected to the rotor windings where as it is not possible in case of SQ I/M

Answer 5

No difference