Simulation model of speed control DC motor using fractional order PID controller

Abstract

DC motor speed can be achieved by changing the armature voltage fed through converter that generally employed with conventional PID. However, conventional PID controller has some disadvantages such as the high starting overshoot and sensitivity to controller gains. On the other hand, fractional order PID has potential to accomplish what conventional PID cannot. In this study, fractional order PID controller was applied to control speed of DC motor. By calculated error that occurred by reference speed and actual speed, fractional order PID brought motor run at desired speed. The parameters of fractional order PID controller (proportional constant, integral constant, derivative constant, derivative order and integral order) are optimally tuned by using Genetic Algorithm, and the optimization performance target is based on Integral Time Absolute Error (ITAE) criterion. Oustaloup's approximation method is used to approximate the fractional order differentiator and integrator. This controller performances are tested in simulation mode using MATLAB/Simulink. Speed response of motor DC are compared between fractional order PID and conventional PID controller. The result of fractional order PID controller could reduce overshoot, settling time and steady state error. With this result, show that fractional order PID controller perform better than conventional PID controller.