AGC of a Multi - area Interconnected System with FACTS and Firefly Optimized 2DOF PID Controller

This paper presents automatic generation control (AGC) of three unequal area thermal systems with single reheat turbine and appropriate generation rate constraints (GRC) in each area. The system dynamic responses for various 2DOF controllers such as 2DOF-PI, and 2DOF-PID are compared. Investigations reveal that responses with 2DOF-PID are better than other. The performance of a two degree of freedom (2DOF) PID controller in presence of several FACTS devices such as Static synchronous series compensator (SSSC), and Interline power flow controller (IPFC) is evaluated for the first time in AGC. Secondary controller gains and other parameters of 2DOF controllers are optimized simultaneously using Fire fly algorithm (FA). Comparison of dynamic responses of the system with 2DOF PID is done with that of with 2DOF PID with SSSC and IPFC reveals that dynamic responses with IPFC are better than others. Sensitivity analysis reveals that the FA optimized 2DOF - PID controller parameters in presence of IPFC at nominal condition of loading and size of step load perturbation (SLP) are robust and need not be reset with wide changes in system loading and SLP.