Induction motor vs Synchronous motor?

Question

In drving load in industries, which 1 is better? Induction motor or Synchronous motor? Dun tell me depends since there must be reason to choose either 1. LoL

Answer 1

I think Synchronous motor is the best one. Because speed can be varied smoothly and it can also be self started by means of some special arrangements such as connecting a capacitor in parallel with the winding.

Answer 2

A synchronous motor operates at precisely synchronous speed as determined by RPM=120f/p where RPM is the speed in revolutions per minute, f is the frequency of the supply voltage in Hz and p is the number of poles created in the motor stator by the windings. An induction motor operates at a speed that is usually about 2 or 3 percent less than synchronous speed when it is delivering rated torque, but at nearly synchronous speed when operating unloaded.

Synchronous motors are only really needed when the speed must be maintained at a precisely constant RPM. Even then, an induction motor with a speed control can be used.

Synchronous motors are used above some power level because they are more efficient and the operating cost savings outweighs the added motor cost and complexity compared to an induction motor. The power level above which synchronous motors are usually preferred is somewhere above a few thousand horsepower. Electric motors have been manufactured is sizes up to 135,000 horsepower. At some power level, induction motors may not be used at all.

Re additional details

"Is synchronous motor better in lifting heavy load then induction motor?"

Lifting a load is something that requires the motor to start, run for a short time while lifting, and then stop when the load has been lifted. An induction motor is easier to start and more tolerant of frequent starting and stopping, so that might make an induction motor a better choice. However, if a very large motor is required, it would be possible to provide a control system to allow a synchronous motor to work just as well.

Answer 3

An induction motor is going to cost less than a synchronous motor.

An induction motor has slip and a synchronous motor does not.

Check out the first paragraph on wiki below.

So which 1 is better has more to do with money than the load.