Frequency control of a two-area RES-integrated power system incorporating a smart transformer using a fractional-order controller

The growing demand for electricity, together with high penetration of renewable energy sources (RES), poses serious operational issues, such as power generation fluctuation, reduced system inertia, and unstable control performance. This article investigates a two-area automatic generation control (AGC) system comprising a thermal system (TS) along with renewable energy sources (RES) that include a solar thermal power plant (STPP) and wind turbine system (WTS), utilizing smart transformers (STs). The article proposed a new fractional order proportional integral minus tilt integral derivative (FOPI-TID) controller. The sperm swarm optimization (SSO) algorithm is used to find the best values of controller parameters. The simulation result shows the superiority of the FOPI-TID controller in comparison to traditional TID and FOPI controllers. It has faster settling responses with reduced overshoots and undershoots. The convergence study further supports the superiority of the proposed approaches. The integration of RES improves the dynamic response of the system, and STs boost overall system performance. Sensitivity analysis shows the resilience of the controller and the good and consistent performance of the FOPI-TID with load fluctuations. Finally, an eigenvalue-based stability analysis is performed under different loading circumstances to confirm the stability improvement gained by the suggested control technique. The obtained findings reveal that the enhanced FOPI-TID controller delivers an increased dynamic performance, robustness and stability, validating its applicability for the studied power-system application.