COMPARISON OF SPEED CONTROL FOR DIFFERENT DC MOTORS USING DIFFERENT POWER AC/DC CONVERTERS

The different uses of DC motors (for both domestic and industrial) make changing the speed from one level to another very important to suit the required speed needed for any particular purpose. The control of this machine can be done using AC/DC power converters. However, the edge which these power converters have over themselves when used to control the speed of these machines are not known. This paper hereby compares using MATLAB/SIMULINK the control of separately excited DC motors, series DC motors and shunt DC motors by AC/DC power converters. The types of AC/DC power converters considered are the half wave, single phase converter drive; single phase, semi-converter drive and single phase, full wave, semi-converter drive. Results show that all motors have their maximum speed with a thyristor firing angle of 0 rad and decrease as the firing angle is increased. For the separately excited DC motors, average speeds change of -94 rpm/rad and -160 rpm/rad were realized for the half wave/semi-converter drives and full wave drives respectively. Furthermore, it can be can be deduced that using the full wave converter drive performs speed changing operations at a faster rate than their half wave or semi converter drive counterparts for the various types of DC motors.