Study on nature inspired optimization techniques for Load Frequency Control (LFC) using Fractional Order PID (FOPID) controller

Abstract

This research presents a comparative study on nature inspired optimization technique for Load Frequency Control (LFC) in a reheat thermal system using Firefly Algorithm (FA) and Cuckoo Search (CS). Load Frequency Control (LFC) is an important control element in the synchronous generator which is tasked to damp frequency oscillation during load changes. LFC plays a very important role in providing quality power in the case of isolated as well as interconnected power systems. The objective of this project is to design a single area of reheat thermal system model and to apply the nature inspired optimization techniques into the system in order to find the optimal solution for the controller used to get the least error by observing the Integral Time Squared Error (ITSE) of the system. This research covers single area of reheat thermal system which uses a Fractional order controller (FOC) and also uses two well-known nature inspired optimization techniques. The Fractional order controller (FOC) possess important properties such as, eliminating steady state error, robustness toward plant gain variations and also good disturbance rejection. Thus, the FOC based PID controller (FOPID) will be beneficial to the power system as it will ensure good system performance. The fitness function Integral Time of Squared Error is chosen to evaluate the error of an area because it shows more advantageous performance compared to the other fitness function such as ITAE and IAE. In this study, a comparative analysis is carried out using the Cuckoo Search (CS) algorithm and Firefly Algorithm (FA) technique to tune the FOPID controller of the LFC for a single area interconnected reheat thermal system. The frequency response and tie line power should be observed in terms of settling time and overshoot/undershoot to evaluate the performance of the tuned FOPID controller and to give the better performance.