Comparative performance assessment of several Fractional Order - Two Degree Freedom controllers tuned using GOA for LFC

摘要

The work puts an earliest effort to compare the performances of different fractional order based feed-forward type two degree of freedom (2DOF-FO) controllers optimized with Grasshopper optimization algorithm (GOA) for the study of load frequency control in interconnected system. As fractional order controllers (FOC) are gaining attention of researchers over integer order controller (IOC) in recent era, so the authors’ main motive in this article is to highlight a comparative performance analysis between three different structures of feed-forward type 2DOF-FOC namely 2DOF-FO-proportional-integral-derivative (2DOF-FOPID), 2DOF-FO-integral-derivative (2DOF-FOID) and 2DOF-FOPI. These controllers are optimally designed through GOA technique. The 2DOF-FOPID controller ensured as the best one over other two controllers in GOA framework even in the presence of nonlinearities for a two area and three areas thermal system. Also, the robustness of the controllers is verified for two area system by applying different physical conditions like a random pattern of step load variations, changing the loading condition in area-1 and the system parameters within a range of ± 20%.