How does DC shunt motor works?

The working principle of a DC Shunt Motor is, whenever a DC motor is turned ON, then DC flows throughout stator as well as the rotor. This current flow will generate two fields namely pole as well as the armature. The commutator overturns the armature current flow direction at ordinary gaps.

What is the reason for reduction in speed of a DC shunt motor from no load to full load?

Since there is a slight variation in speed of the shunt motor from no load to full load and this slight variation in speed can be made up by inserting resistance in the shunt field and so reducing the flux.

How the speed of the DC shunt motor can be decreased?

Flux control method It is already explained above that the speed of a dc motor is inversely proportional to the flux per pole. Thus by decreasing the flux, speed can be increased and vice versa. To control the flux, a rheostat is added in series with the field winding, as shown in the circuit diagram.

What are the factors affecting the speed of a DC shunt motor?

The above equation shows that the speed depends upon the supply voltage V, the armature circuit resistance Ra, and the field flux Ф, which is produced by the field current. In practice, the variation of these three factors is used for speed control.

What happens when a DC motor loses power to its shunt field?

From what I understand the loss of the field current, and thus the field itself, will result in a decrease in back EMF on the armature. This will allow a higher current to flow through the armature, and also cause the motor to speed up.

Why is the speed of a DC shunt motor constant?

Detailed Solution. In case of DC shunt motor, flux is practically constant as the field is parallel to the armature. If the load is increased, then the speed of the motor will remain almost constant because the field current remains almost constant. So that it is also known as constant speed motor.

Which affects the terminal voltage of a DC shunt motor?

Explanation: The speed reduced slightly due to armature drops practically. 2. Mark the correct option which affects the terminal voltage of a dc shunt motor. Explanation: If the dc motor has compensating winding, flux will remain constant regardless of load.

How do you control the speed of a DC shunt motor?

In the shunt motor, speed can be controlled by connecting a variable resistor Rc in series with the shunt field winding. In the diagram below resistor, Rc is called the shunt field regulator. Figure: (a) Speed control of a D.C. shunt motor by variation of field flux.