Automatic generation control of an interconnected CCGT-thermal system using stochastic fractal search optimized classical controllers

During the past few decades, frequency regulation of combined cycle gas turbine (CCGT) has become an interesting issue of research. A larger power system model experiences many challenges when base-loaded CCGT unit is incorporated in it. This article presents the load frequency regulation of CCGT model in conjunction with thermal units in an unequal 3-area interconnected system. The control strategy of CCGT plant includes temperature and air flow controllers that are designed on the basis of minimization of area control error. The main drive of proposed control strategy is to successfully tackle the system dynamics during step and realistic load disturbances. The eigenvalues of proposed system commensurate with dynamic stability. A new metaheuristic algorithm known as stochastic fractal search has been applied for simultaneous optimization of classical controller (proportional [PI], proportional-integral [PI] and proportional-integral-derivative [PID] gains, and other parameters such as governor speed regulation parameter [R_i], frequency bias [B_i]). Comprehensive simulations are performed to ensure stable system dynamics with easier and cheaper realization of governor, and higher values of B_i in respective areas and robustness of stochastic fractal search optimized PID controller.