Solution to automatic generation control problem using firefly algorithm optimized IλDμ controller

Present work focused on automatic generation control (AGC) of a three unequal area thermal systems considering reheat turbines and appropriate generation rate constraints (GRC). A fractional order (FO) controller named as (ID mu)-D-lambda controller based on crone approximation is proposed for the first time as an appropriate technique to solve the multi-area AGC problem in power systems. A recently developed metaheuristic algorithm known as firefly algorithm (FA) is used for the simultaneous optimization of the gains and other parameters such as order of integrator (lambda) and differentiator (mu) of (ID mu)-D-lambda controller and governor speed regulation parameters (R). The dynamic responses corresponding to optimized (ID mu)-D-lambda controller gains, lambda, mu, and R are compared with that of classical integer order (10) controllers such as 1, PI and PID controllers. Simulation results show that the proposed (ID mu)-D-lambda controller provides more improved dynamic responses and outperforms the IO based classical controllers. Further, sensitivity analysis confirms the robustness of the so optimized (ID mu)-D-lambda controller to wide changes in system loading conditions and size and position of SLP. Proposed controller is also found to have performed well as compared to IO based controllers when SLP takes place simultaneously in any two areas or all the areas. Robustness of the proposed (ID mu)-D-lambda controller is also tested against system parameter variations. (C) 2013 ISA. Published by Elsevier Ltd. All rights reserved.