Comparison Charts
| Synchronous Motor | Induction Motor |
|---|---|
| The synchronous motor is not a self-starting motor some external means are required for its starting. | The Induction motor is the self-starting motor and no special means is required for its starting. |
| The average speed of the synchronous motor is constant and independent of load. | The speed of the induction motor falls with an increase in load and is always less than synchronous speed. |
| The synchronous motor is a doubly excited motor. | The induction motor is the single excited motor. |
| The synchronous motor can be operated both the power factors; lagging and leading power factors. | The induction motors operated at only a lagging power factor which become very poor at light loads. |
| In synchronous motors, armature winding coils are supplied from alternating supply and field winding coils are supplied from the Direct current. | In an induction motor, stator winding is supplied from alternating current only. |
| The DC excitation requires in synchronous motors. | The Dc excitation is not required in induction motors. |
| In a synchronous motor, speed control is not possible. | In an induction motor, speed control is possible to a small extent. |
| The synchronous motor is used for supplying mechanical load as well as for power factor improvement. | The induction motor is used for supplying mechanical load only. |
| The synchronous motor's torque is less sensitive to changes in supply voltage. | The induction motor's torque is more sensitive to changes in supply voltage. |
| In a synchronous motor, breakdown torque is proportional to the supply voltage. | In an induction motor, breakdown torque is proportional to the square of the supply voltage. |
| The synchronous motor is more efficient than the induction motor. | The efficiency of induction motor is less than the synchronous motor. |
| The synchronous motor is more complicated and costs more comparatively. | The induction motor is simple and costs less comparatively. |
| The slip rings and brushes are required in synchronous motors. | The slip rings and brushes are not required in induction motors. |
| The synchronous motor always runs at synchronous speed, so it's called a synchronous motor. | The induction motor always runs at a speed less than synchronous speed, so the induction motor is called an asynchronous motor. |
| The synchronous motor works on the principle of magnetic locking. | The principle of induction motor is laws of electromagnetic induction. |
| In a synchronous motor, there is zero slips occur. | In induction motor, there is a different slip that occurs. |
| There is maximum maintenance required in a synchronous motor. | There is minimal maintenance required in the induction motor. |
Points about Difference between Induction Motor and Synchronous Motor
1. The synchronous motor is not a self-starting motor some external means are required for its starting. The Induction motor is the self-starting motor and no special means is required for its starting.
2. The average speed of the synchronous motor is constant and independent of load. The speed of the induction motor falls with an increase in load and is always less than synchronous speed.
3. The synchronous motor is a doubly excited motor. The induction motor is the single excited motor.
4. The synchronous motor can be operated both the power factors; lagging and leading power factors. The induction motors operated at only a lagging power factor which become very poor at light loads.
5. In synchronous motors, armature winding coils are supplied from alternating supply and field winding coils are supplied from the Direct current. In an induction motor, stator winding is supplied from alternating current only.
6. The DC excitation requires in synchronous motors. The Dc excitation is not required in induction motors.
7. In a synchronous motor, speed control is not possible. In an induction motor, speed control is possible to a small extent.
8. The synchronous motor is used for supplying mechanical load as well as for power factor improvement. The induction motor is used for supplying mechanical load only.
9. The synchronous motor's torque is less sensitive to changes in supply voltage. The induction motor's torque is more sensitive to changes in supply voltage.
10. In a synchronous motor, breakdown torque is proportional to the supply voltage. In an induction motor, breakdown torque is proportional to the square of the supply voltage.
11. The synchronous motor is more efficient than the induction motor. The efficiency of induction motor is less than the synchronous motor.
12. The synchronous motor is more complicated and costs more comparatively. The induction motor is simple and costs less comparatively.
13. The slip rings and brushes are required in synchronous motors. The slip rings and brushes are not required in induction motors.
14. The synchronous motor always runs at synchronous speed, so it's called a synchronous motor. The induction motor always runs at a speed less than synchronous speed, so the induction motor is called an asynchronous motor.
15. The synchronous motor works on the principle of magnetic locking. The principle of induction motor is laws of electromagnetic induction.
16. In a synchronous motor, there is zero slips occur. In induction motor, there is a different slip that occurs.
17. There is maximum maintenance required in a synchronous motor. There is minimal maintenance required in the induction motor.