A novel cascade controller for load frequency control in a multi-sources microgrid

The increasing integration of renewable energy sources (RESs) into the power grid reduces system inertia, leading to frequency instability due to RES and load variability. To address this, a novel cascaded controller, (PIDn+PDn)-PI, is proposed for load frequency control (LFC) in a microgrid comprising wind turbines, photovoltaic systems, solar thermal power, aqua electrolyser, diesel generator, electric vehicle, and hybrid storage (supercapacitor & battery). The controller's parameters are optimised using the particle swarm optimisation (PSO) algorithm. MATLAB/Simulink simulations demonstrate its superiority in settling time (0.0063 s), maximum overshoot (1.07 × 10-4), and maximum undershoot (-1.58 × 10-3) compared to PI, PIDn, PDn-PI, and nonlinear sliding mode controllers. A sensitivity analysis with electric vehicle gain variations (0.1, 1, and 10) confirms robustness. The results highlight the efficiency and reliability of the proposed controller in ensuring frequency stability in microgrids with high RES penetration.