The Construction of Synchronous Motor | Principle Operation of a Synchronous Motor

What is Synchronous Motor?

This motor works as an alternator to convert alternating electrical energy into mechanical energy. The speed of rotation of this motor remains constant compared to the rest of the motor, which means that this motor does not increase/decrease. This is a feature of this motor. Synchronous motor is also called synchronous motor in other words.The Construction of Synchronous Motor

Construction of a Synchronous Motor

The structure of the synchronous motor DC. It is similar to a machine where there is no difference in the structure of the generator and engine, and there is no difference in the alternator and synchronous motor structure. The synchronous motor structure consists of two parts –

(a) Stator – The stationary part of the motor is called a stator. It has a triple star or delta-connected coil. The alternating AC supply stimulates it.

(b) Rotor – The rotor has a field winding, whose structure is of salient or projected pole or non-salient or cylindrical type. Its field winding is stimulated by slippering by giving a separate DC supply.

The Construction of Synchronous Motor

The design of the synchronous motor mainly consists of the same parts like the alternator. The stator coil is a circular coil that is coiled according to the magnetic poles. Picture | According to, the ring of four bars is shown in the stator. Eye hooks are used to lift or reposition the motor and place it on the foundation. Feet or feet are attached to the channel to fit the engine permanently. In this, the damping coil is done at the ends of the rotor.

(i) In this, AC supply is given to the stator of the motor.
(ii) DC supply is given to the field poles of the rotor. A DC supply makes a pair of magnetic poles.
(iii) The rotational force to drive the rotor is the interaction of the stator’s magnetic field and the rotor.
(iv) When the S pole of the rotor is in front of the N pole of the stator, and this is the order, then the motor is started when the poles of the rotor interlocking with the magnetic poles of the stator rotate at the same speed.

Principle Operation of a Synchronous Motor

An asynchronously rotating magnetic field is produced in the stator coil of a synchronous motor when an alternating current is supplied to it. In Figure 2, suppose that the poles Ns and Ss are moving with synchronous speed in a two-pole stator of a synchronous motor.

Suppose the magnetic field of the stator is rotating clockwise. When a directional current is given to the rotor field, it will also produce a magnetic field of constant polarity.

In Figure 2, suppose that the Ns pole generated by the stator in the first half positive cycle is at point A and the Ss pole is at point B. In this case, the rotor will get repulsive force in an anti-clockwise direction, but in the remaining half negative cycle (Figure 3), the stator pole Ns will rotate to point B, and the Ss pole will come to point A. In this case, the force will be in the clockwise direction opposite the rotor’s first position. Thus the farther the rotor has moved, the more it will come back. Therefore the rotor will remain at its former position.

The formula for the speed of rotation of a synchronous motor is –
N = 120f/P

The Construction of Synchronous Motor

If the rotor is rotated by some other means at the flux speed of the stator and again the excitation current is given to the rotor field, it will continue to rotate at a uniform and synchronous speed.

The Construction of Synchronous Motor

Suppose that as in Fig. 3(a), the moment the rotor is brought to synchronous speed and given a directional exciter current, it produces an S pole in front of point A and N pole in front of point B. When the bars Ns and Ss of the stator reach A respectively while rotating, the rotor will rotate with it and interlocked and rotate with it.

Applications of Synchronous Motor

These motors increase the power factor in factories where multiple induction motors are installed, thereby reducing the power factor. Using it there increases the power factor. Using it there increases the power factor. Transformers are not overloaded. It is also used in rubber mills, mines, paper mills and big industries to get mechanical strength.

(i) To run the MG set at a constant speed
(ii) To operate the frequency converter primer
(iii) To drive compressor, pump, line shaft.

you learned today What is Synchronous Motor, The Construction of Synchronous Motor, Principle Operation of a Synchronous Motor, Applications of Synchronous Motor.

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