Enhancing frequency stability in power systems through DO-optimized FOPI-PIDA-controlled STATCOM for wind energy integration

Abstract

This research endeavors to enhance the frequency stability of power systems connected to wind energy under various disturbances, such as load variations and generator outages due to grid faults, by dynamically regulating reactive power injection. The study introduces an advanced control strategy employing a Fractional Order Proportional-Integral with Proportional-Integral-Derivative-Acceleration (FOPI-PIDA) controller, integrated with a static synchronous compensator (STATCOM). The controller is meticulously optimized using the Dandelion Optimizer (DO), a cutting-edge metaheuristic algorithm selected for its exceptional convergence and robustness. The proposed DO-tuned FOPI-PIDA-controlled STATCOM effectively stabilizes system frequency during load shifts or generator failures, maintaining frequency deviations within acceptable limits. The controller’s efficacy is rigorously validated through time-domain simulations in MATLAB/SIMULINK across two benchmark systems: the Kundur two-area test system and the IEEE 39-bus test system, both coupled with wind energy integration. Stability metrics such as Maximum Overshoot (M.O.), Maximum Undershoot (M.U.), and Steady-State Frequency (S.S.) are assessed to quantify performance. Comparative analysis highlights the superior frequency regulation capabilities of the DO-optimized FOPI-PIDA-controlled STATCOM compared to the conventional PIDA-based STATCOM, which was previously tuned using the Marine Predator Algorithm (MPA). For example, in the IEEE 39-bus system with wind integration, during a 20 % load loss, the proposed controller limits the M.O. to 60.47 Hz and the S.S. to 60.34 Hz, outperforming the MPA-tuned controller’s 60.51 Hz and 60.36 Hz. Similarly, during the disconnection of Generator 2, the proposed controller sustains the M.U. at 59.62 Hz and the S.S. at 59.70 Hz, surpassing the PIDA controller's 59.57 Hz and 59.66 Hz. These results affirm the robustness and adaptability of the proposed control scheme for ensuring reliable frequency regulation in wind-integrated power systems.