Dr. Syed Saad Azhar Ali Control Systems Dr. Syed Saad Azhar Ali

Mathematical model and Transfer Function of DC motor The dc motor is a component that converts direct current (dc) electrical energy into rotational mechanical energy, which is available to drive an external load.

Dr. Syed Saad Azhar Ali DC motor

Dr. Syed Saad Azhar Ali Continued… The air-gap flux of the motor is proportional to the field current,provided the field is not saturated, so that

Dr. Syed Saad Azhar Ali Continued… The torque developed by the motor is assumed to be related linearly to Φ and the armature current

Dr. Syed Saad Azhar Ali Continued… Field Controlled DC motor

Dr. Syed Saad Azhar Ali Continued… Field Controlled DC motor Now considering… And finding the Laplace Transform

Dr. Syed Saad Azhar Ali The back electromotive-force voltage which is induced to oppose the input voltage to the armature is (for a constant field)

Dr. Syed Saad Azhar Ali Continued… Field Controlled DC motor The field current is related to the field voltage as

Dr. Syed Saad Azhar Ali Continued… Field Controlled DC motor The motor torque T m (s) is equal to the torque delivered to the load. This relation may be expressed as

Dr. Syed Saad Azhar Ali Continued… Field Controlled DC motor The load torque for rotating inertia is Equating Tm(s) to TL(s) and making use of the above equations result in the transfer function

Dr. Syed Saad Azhar Ali Block Diagram

Dr. Syed Saad Azhar Ali Assignment 1 Part II Obtain the TF for the Armature Controlled DC motor along with its block Diagram