Difference Between Induction Motor And Synchronous Motor

The fundamental difference between these two motors is that the speed of the rotor relative to the speed of the stator is equal for synchronous motors, while the rotor speed in induction motors is less than its synchronous speed. This is why induction motors are also known as asynchronous motors.

In This Article We Will Compare Induction And Synchronous Motor.

(i) Synchronous Motor
(ii) Asynchronous Motor

Broadly, AC Motor can be categorized into 2 parts

Asynchronous Motor Is Also Popularly Known As Induction Motor. There Is A Lot Of Difference Between These Two Categories. So, Lets Discuss Them.

1. Synchronous Motor Is A Doubly Excited Machine, Whose Armature Winding Is Energised From AC Source And Its Field Winding Is Energised From DC Source.

Whereas Induction Motor is a single excited machine and its winding are energised from an AC source.

2. Speed of Synchronous motor is independent of the load and always runs at synchronous speed.

Whereas speed of Induction Motor falls with the increase in load and is always less than the synchronous speed.

3. Synchronous Motor is not self- starting, some external means are provided to synchronize the motor with the AC supply.

Whereas Induction motor can develop self starting torque and are self starting.

4. Synchronous Motor can be operated under the wide range of power factor (both leading and lagging), by changing the field excitation.

Whereas Induction Motor is only operated at lagging power factor and it becomes very poor at high loads.

5. Synchronous Motor is more efficient than the Induction Motor for the same input and voltage rating.

6. Synchronous Motor Is Costlier Than He Induction Motor Of The Same Output And Voltage Rating.

7. Synchronous Motor finds its application in the field of power factor correction, drive mechanical loads that requires constant speed etc.

Whereas Induction Motor is only used for driving mechanical loads, traction.