How can you change the speed of a separately excited DC motor?

The speed of separately excited dc motor can be control by changing the armature voltage and changing field flux. Due to this the speed can be controlled for below rated speed and speed above the rated speed, respectively.

How does a change in the voltage across the armature of a DC motor affect the speed of the armature?

Speed of a dc motor is directly proportional to the back emf Eb and Eb = V – IaRa. That means, when supply voltage V and the armature resistance Ra are kept constant, then the speed is directly proportional to armature current Ia. Greater the resistance in series with the armature, greater the decrease in speed.

How does voltage affect DC motor speed?

DC motor circuit. From the analysis above, we can see that when the load (torque) on the motor is constant, speed is directly proportional to supply voltage. And, when the voltage remains constant, an increase in the load (torque) on the motor results in a decrease in speed.

How will the speed of the motor change with increasing the value of armature voltage?

By having more current in the armature there is more torque and the armature increases speed until it reaches a back end that is nearly equal to the applied voltage.

How does a separately excited motor work?

A separately excited dc motor is a motor whose field circuit is supplied from a separate constant-voltage power supply, while a shunt dc motor is a motor whose field circuit gets its power directly across the armature terminals of the motor. Hence, the motor speed will slow down.

What is armature voltage?

Armature voltage is the voltage developed at the terminals of the armature winding of an AC or a DC machine during generation of power.

What is the relationship of the armature voltage and field current?

Based on the experiment I conducted, the data shows that the armature voltage is directly proportional to the field current.

How does the speed of a DC shunt motor vary with armature voltage and field current?

In the armature control method, the speed of the DC motor is directly proportional to the back emf (Eb) and Eb = V- IaRa. When supply voltage (V) and armature resistance Ra are kept constant, the Speed is directly proportional to armature current (Ia).

What is the relation between armature voltage and speed?

How does a separately excited DC motor work?

Separately excited dc motor has field coils similar to that of shunt wound dc motor. The name suggests the construction of this type of motor. Here, the field coil is energized from a separate DC voltage source and the armature coil is also energized from another source.