Design of Optimal FOPID Controller for Speed Control of DC Motor Including Drive and Chopper Dynamic Considering Multi-Objective Optimization Using Water Cycle Optimization Algorithm

DC motors have a variety of applications including robotic arms. These DC motors have simple structure and long life. Therefore, the precise speed control for increasing performance and industrial applications is of great importance. This paper is devoted to designing a fractional PID controller in order to speed control of a DC motor by considering the drive and chopper dynamics. Remarkably, the voltage applied to the DC motor armature can be controlled using a chopper. From a control point of view, the dynamics of the chopper could complicate the system dynamics, and from a practical point of view, it could reduce the ripple of the armature current. This improves the transient response and results in better speed regulation. In addition, as a novelty, to adjust the fractional order PID controller coefficients a new optimization approach called water-cycle optimization (WCA) algorithm by considering a multi-objective criteria is employed. The results obtained are compared with the artificial bee colony and particle swarm optimization algorithm. The results show that the fractional order PID controller optimized by the WCA algorithm performs better in terms of rise-time, overshoot and steady state error.