# Why is it possible for a synchronous motor to operate at the speed of the rotating magnetic field?

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## Is it possible to operate a synchronous motor on any other speed than the synchronous speed?

A synchronous motor with only a field winding carrying a direct current would not be self-starting. At any speed other than synchronous speed, its rotor would experience an oscillating torque of zero average value as the rotating magnetic field repeatedly passes the slower moving rotor.

## Why the speed of the motor is less than the synchronous speed?

Actual speed of the induction motor will be less than the synchronous speed. The reason for this is if the armature turns exactly at synchronous speed, then the magnetic field of the stator windings no longer cuts the rotor windings. Under this condition, no current would be induced to the rotor windings.

## How does a synchronous motor achieve synchronous speed?

The speed of a synchronous motor is dependent on the frequency of the power source and the number of poles the stator has. RPM increases directly with frequency and inversely as the number of poles. … The motor will run at synchronous speed and will not have the slip required by the other three-phase induction motors.

## What is the advantage of synchronous motor?

The advantage of using synchronous motor is the ability to control the power factor. An over excited synchronous-motor has leading power factor and is operated in parallel to induction motors thereby improving the system power factor. Speed remains constant irrespective of the loads in synchronous motors.

## Can induction motor run at synchronous speed?

So, theoretically, the Induction motor can never run at synchronous speed. … But due to the reduction of speed, again lag influx will be achieved, and the motor will continue to move at this speed due to flux difference between rotor and stator. In short, an induction motor cannot run at induction speed.

## Is rated speed synchronous speed?

The synchronous speed refers to the stator rotating magnetic field, which depends on the number of poles and frequency. … Rated speed is the base speed minus the slip at full rated load. An induction motor slows as it is loaded. The induction motor must run at a speed below the revolving stator field flux.

## What is relation between synchronous speed and frequency?

The synchronous speed of the motor depends on; Frequency of the supply source. Number of poles of the motor.

Synchronous speed Formula.

No. of Poles Frequency (50 Hz) Frequency(60 Hz)
2 3000 3600
4 1500 1800
6 1000 1200
8 750 900

## What is the value of synchronous speed?

The synchronous speed is the speed of the revolution of the magnetic field in the stator winding of the motor. It is the speed at which the electromotive force is produced by the alternating machine.

Synchronous Speed.

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Number of Poles Synchronous Speed NS in r.p.m
10 600
12 500

## What is called synchronous speed?

: a definite speed for an alternating-current machine that is dependent on the frequency of the supply circuit because the rotating member passes one pair of poles for each alternation of the alternating current.