Multi — Area AGC with AC/DC link and BES and Cuckoo Search optimized PID controller

This paper presents automatic generation control of three unequal area hydro-thermal systems with appropriate generation rate constraints in each area and each area is interconnected with AC/DC transmission links. Electric governor is considered in hydro area. Battery energy storage (BES) system is incorporated for the first time in 3-area hydro thermal system and areas are interconnected with AC/DC link. The dynamic responses of the system with BES are compared with that without BES. The PID controller is used as the secondary controller. The controller gains are optimized using a more recent powerful evolutionary optimization technique called "Cuckoo Search". Investigations reveal that dynamic responses of the system with BES are better than without BES. The sensitivity analysis reveals that the optimum controller gains in presence of BES obtained at nominal conditions and at nominal parameter are robust and need not be reset to uncertain change in system loading, inertia constant and location and magnitude of step load perturbation.