FOPTID+1 controller with capacitive energy storage for AGC performance enrichment of multi-source electric power systems

The demand for power increases during the peak hours and the power supply can't exceed its limitations. This results into mismatch between the supplied and demanded powers causing fluctuations in the frequency. Extreme power-frequency deviations may cause power system blackouts. To maintain the constant frequency of power system, automatic generation control (AGC) should be embedded with a reliable controller. In this paper, a fractional order proportional tilt integral derivative plus one (FOPTID+1) controller is introduced in the design of AGC to retain frequency constancy. This controller has the ability to regulate the frequency hastily during load disruptions. The controller parameters are optimized by exploiting global neighbourhood algorithm (GNA). Firstly, the investigation is directed on a one-area multi-source thermal-hydro-gas generating system. To authenticate the expandability of the method, the study is then extended to multi-source interconnected two-area thermal-hydro-gas power system without/with nonlinearities. The dominance of the suggested controller is recognized over various recently published results of I/PI/PID/TID/FOTID and GNA tuned PID/FOPID controllers. Inspection of results authorizes the worthier performance of FOPTID+1 over other controllers regarding least overshoot/undershoot/settling time of frequency/tie-line power change and error criteria at disturbances. To further advance the system performance, capacitive energy storage (CES) units are incorporated to compensate the power demanded by the load disturbances. The obtained results demonstrate that CES is capable to improve system performance effectively. With CES, FOPTID+1 produces less cost function value for both onearea (9.52%) and two-area (8.97% for linear and 11.38% for nonlinear) systems. The control system stability is verified by the study of bode diagram. The resilience behaviour of the controller is confirmed by the stout conduct of controller under +/- 25% variation of system parameters and tie-line outages.