Three Phase Induction Motors

A three  phase induction rotor  consists  a stators  and a motor stator has balanced three  phase  winding. These windings  are distributed in the  stator slots. These are displaced by 1200in space with respect to each  other. According  to their rotor  three  phase induction motors are classified into followings  types:

a.Squirrel  cage induction motor

b.Slip ring  induction motor

In  SCIM the rotor  windings consists of uninsulated conductors in the form  of copper  or aluminium  bars embedded in the semi  closed. These solid  bars are short  circuited at both  ends  by end ring of the same  material. Without the rotor  core  the rotor   bars and end ring look  like  the cage of a squirrel hence  the name  squirrel cage induction motor. The rotor  bars  form a  uniformly distributed  winding  in the rotor  slots

A  3- phase   induction motor  receives  electrical  energy from  on alternating voltage source therefore it is a simply  excited machine. The stator carries the field winding  and armature winding (in  which the  working emf is induced by the working flux) is on the rotor. This motor  has come  to be called  as induction motor  because stator  delivers energy to rotor  by means of induction.