AGC of a multi-area hydro-thermal system with BES and firefly optimized PID controller

This paper presents automatic generation control of three unequal area hydro-thermal systems. Appropriate generation rate constraints are considered in each area. Proportional - Integral - Derivative (PID) controller is used as the secondary controller in the areas. A Battery Energy Storage (BES) system is incorporated in Area1 and the system dynamic responses are compared with that of without BES system. Selection of position of BES in interconnected multi area system has been done first time as an individual and observed that BES in Area-1 with 1% SLP is the best. The PID controllers gains are optimized simultaneously using a more recent evolutionary computational technique called firefly algorithm. Investigations reveal that dynamic responses of the system with BES are better than without BES. Sensitivity analysis reveals that the optimum parameters obtained at nominal conditions are quite robust and need not be reset with wide change in system loading and change in step load perturbation (SLP). The system dynamics is evaluated by considering 1% SLP in area1.