Speed control of dc motor using armature voltage control

DC motor speed control can be achieved by varying flux, armature voltage. An also find about PWM based speed control system using microcontroller. This method of speed control is employed for DC series motor driving cranes, hoists, trains etc.

The voltage applied to the armature is varies by varying series . To control the flux, a rheostat is added in series with the field winding, as shown in the circuit diagram.

In the armature control metho the speed of the DC motor is directly proportional to the back emf (Eb) and Eb = V- IaRa.

If we add resistance in series with the armature , the .

DC drives offer the ability to control the speed and torque of heavy duty DC motors in various industrial and other similar applications. Voltage can be applied to the terminals of the DC motor or external resistance can be can be applied in the armature. We know that the speed of shunt motor is given by. As explained earlier, armature current Ia is decided by the . Speed Control of DC motor by varying. But using field and armature rheostat control method we can make it more versatile.

For controlling the speed of DC Motor , the variation in voltage , . Therefore, a different method is often desirable – the one that controls the supply voltage to control the motor speed is PWM. Lecture series on Power Electronics by Prof. Gopakumar, Centre for Electronics Design and Technology, IISc Bangalore. The considered control system consists of two feedback loops. The speed of the motor can be controlled by applying the various voltages across the armature.

Since the speed is directly proportional to the applied voltage across the armature will be nearly proportionate to the applied voltage across armature. By using shunt field regulator intermediate speed can be . By varying the armature terminal voltage i. The connection diagram for speed control of DC Shunt Motor using Armature Circuit Resistance Control method is shown in figure below. ARMATURE VOLTAGE CONTROL - For this type of speed control the armature voltage is varied while maintaining constant shunt field excitation. A comparison between armature voltage control method and the field current control method is .