Ac motor are classified into two main type.(a) Synchronous Motor and (b) Asynchronous motor.Generally asynchronous motors are called induction motor.Synchronous and asynchronous both motor are different in every manner.Here the difference between these motor are given below.
Constructional Difference :Physical Difference of Induction and Synchronous Motor
Synchronous Motor-Synchronous motor has two main part:-(1) Stator and (2) Rotor.
Stator is a house where three phase armature winding are puts in the slots of the stator core and these windings are energies by external source.Rotor is the rotating part of the electrical machine.it has set of salient poles excited by direct current to form alternate magnetic poles.The exciting coils are connected in series to two slip rings and direct current is fed into the winding from an external exciter which is mounted on the rotor shaft.The stator is wound for the same number of poles as the rotor poles.
Induction Motor-As that of synchronous motor,induction motor has also two main part (a) Stator and (b) Rotor.
Stator is the static part of the induction machine .it is made of high grade alloy lamination to reduce eddy current loss.the stator carries a three phase winding which is fed from a three phase supply.These three phase winding are arranged in such a manner i the slots that it produce a rotating magnetic field.To achieve this mention purpose these three winding are are arranged at 120 degree apart. Rotor is the rotating part of the induction machine.it is also made up of high grade alloy of thin lamination .Rotor of three phase induction motor consists of cylindrical laminated core with parallel slots and that can carry conductor.Conductors are heavy either copper or aluminium bars which fits in each slots and they are short circuited by the end rings.
Difference in working Principle
Working of Synchronous Motor-When a three phase supply is connected to the stator winding of the motor,then there is a rotating magnetic flux is set up in the stator winding.The speed at which this magnetic field rotate is called synchronous speed.when this rotating magnetic field is coupled with the pole of rotor then the motor start to run and its run at synchronous speed.
Working of Induction Motor-When a three phase supply is connected to the stator of the induction motor then there is a three phase rotating magnetic flux is setup.When this varying magnetic flux cuts the conductor of the the rotor then an EMF is induced in the rotor conductor.this rotor conductors are short circuited at the end and hence a alternating current starts to flow in the rotor conductor and this alternating current produce a torque which tends to move the rotor conductor.
