Simulation of Chopper fed PID controlled dc motor drive system

Abstract

Several control strategies are employed in dc motor drive system viz adding extra resistance or rheostat control, analog control with error amplifier and controller etc. In this simulation we are aiming at the control strategy of the speed of DC motor, using chopper circuit and PID control methods. Here using electronic switches and free-wheeling diodes, the dc input to the motor is made variable dc, by means of chopper operation, to achieve armature voltage control. A Proportional-Integral-Derivative (PID) controller is a feedback control mechanism, used in large industry applications. Such PID operations reduce different types of steady state and transient errors present in the system and improve the performance. By proper choice of proportional, derivative and integral gain values (Tuning method), appropriate switching sequence of the chopper circuit is achieved; which in turns controls the speed of the motor. MATLAB domain is employed to construct the simulation circuit and different variations of speed are plotted.