Why do we use separately excited DC motors?

Separately excited DC motors are often used as actuators in trains and automotive traction applications. For their constant speed characteristics, shunt DC motors are used in fixed speed applications such as fans. square of armature current), they can be used in applications that require high starting torque.

What is the difference between the DC series motor and the DC separately excited motor in view of torque and armature current?

In separately excited DC motors, the field winding can be excited from a different source of supply altogether. In a series motor both the armature and field winding are connected in series with each other.

How the speed control is achieved in 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. The Armature voltage can be controlled by Using IGBT based chopper.

What are separately excited generators used for?

Applications of Separately Excited DC Generators These are used in speed regulation tests. These generators operate in a stable condition with any change in field excitation. Therefore, they are also used in supplying power to the DC motors, whose speed being to be controlled.

What is a separately excited DC generator?

A separately excited DC generator is the one whose field winding is supplied by an independent external DC source (like a battery). The magnitude of generated voltage depends upon the speed of rotation of armature and the field current, i.e., greater the speed and the field current, higher is the generated voltage.

Why is the DC motor preferred over AC motor?

D.C. motor is preferred over an A.C. motor when we need variable speed operation because As in DC series motor field winding and armature winding is in series. So whenever armature current changes field current also changes as they are same due to which its torque changes rapidly and we get a variable speed.

How can a separately excited dc motor be controlled using a chopper?

The speed of Separately Excited DC motor is controlled to a maximum of its rated speed using chopper as a converter. The speed controller used is Proportional Integral type which reduces steady state error and provides fast control. The parameters of the speed controller have been designed using control system theory.

What is DC separately excited generator?

What are DC shunt motors used for?

DC Shunt Motor Applications These motors are used wherever stable speed is required. This kind of DC motor can be used in Centrifugal Pumps, Lifts, Weaving Machine, Lathe Machines, Blowers, Fans, Conveyors, Spinning machines, etc.