Application of SCA Tuned FFOPI Controller for LFC of Nonlinear Power System

Load Frequency Control popularly known as LFC has a significant role in preserving the system stability and providing consistent and quality power to the customers. This paper investigates the LFC of a three area reheat thermal system with nonlinearity such as generation rate constraint (GRC) under load fluctuation. At first, fuzzy proportional integral (FPI) controller is used for the purpose and the gains of the controller are tweaked by the sine cosine algorithm (SCA) but the controller fails to stabilize the system due to the system nonlinearity. So, the improved version of FPI controller, known as fuzzy fractional order proportional integral (FFOPI) controller is introduced and tuned by the particle swarm optimization (PSO) and SCA independently. For implementing the optimization process, integral time absolute error (ITAE) is selected as the objective function (OF). The response parameters of the frequency and tie-line power are analyzed with PSO tuned FFOPI (PSO-FFOPI) and SCA tuned FFOPI (SCA-FFOPI) controller and it is established that SCA-FFOPI controller delivers improved control performance than the other controller.