Multi-Objective PI controller design with an application to speed control of Permanent Magnet DC motor drives

This paper proposes a Multi-Objective Optimization (EMOO) algorithm is used to tune the Proportional Integral (PI) speed regulator in the Permanent Magnet DC (PMDC) motor drive system It aims at achieving good robustness and struck at global optima. Calculus based methods including gradient approaches mainly search for local optimum solutions, rather than global optimum. Due to the drawbacks that exist in calculus based methods, the proposed method is employed for multiobjective optimization problems. The robustness features of the proposed design approach are verified using multi-objective evolutionary Non-dominated Sorting Genetic Algorithm (NSGA-II) and Non-Dominated Sorting Particle Swarm Optimization (NSPSO). Conflicting objectives considered are rise time and settling time for multi-objective optimization. Speed control of motor of Permanent Magnet DC Motor is achieved with PI speed regulator tuned using NSGA-II and NSPSO. Finally, the Pareto Optimal solutions obtained show the effectiveness of NSPSO in comparison with NSGA-II in design of PID controllers for a highly non-linear process.