Speed control of DC motorusing chopper

Abstract

DC motors form the backbone of many industries and as such their speed control becomes of immense importance. It has been found that many of these applications perform with a greater efficiency when the motors are fed from a source of variable dc power. In this report we analyze the separately excited dc motor using, MATLAB (Simulink), for speeds above and below the rated speed using a chopper circuit. The chopper circuit receives a signal from the firing circuit and then gives a signal to the armature voltage controller of the separately excited dc motor and the speed is accordingly increased or decreased. In this system we use two different control loops, in for speed and another for current. Here we use a proportional integral type control as in this the delay gets removed and the control provided is very fast. The dc motor is modelled and the control loops are laid out and then onwards we design the drive system. There after the simulations of the system have been carried out and analyzed under varying circumstances of speed and load torque.