Optimal frequency control in renewable-dominated multi-microgrids using an integral filtered derivative tilted controller optimised via salp swarm algorithm

• Proposed I λ DN-T controller enhances load frequency control in multi-microgrids. • SSA optimizes I λ DN-T parameters, improving stability and transient performance. • Robust against nonlinearities, load changes, and communication time delays. • Achieves lower overshoot and settling time than PID, TID, and IDN-T controllers. • Validated experimentally using real-time OPAL-RT hardware-in-the-loop setup. Modern renewable-dominated distributed energy resources demand advanced control strategies for effective load frequency control (LFC). To meet this requirement, a novel integral filtered derivative-tilted (I λ DN-T) controller is proposed. The primary goal of LFC is to ensure reliable, high-quality power delivery to consumers while maintaining system frequency within specified limits and minimizing tie-line power deviations. The Salp Swarm Algorithm (SSA) is used to optimise design parameters of the I λ DN-T controller. The proposed hybrid multi-microgrids consists of gas-hydro-nuclear generating subunits, incorporating nonlinearities such as generation rate constraints, governor dead band (GDB), and time delays. To evaluate the effectiveness of the proposed I λ DN-T + SSA based control strategy, a comparative study is conducted between the dynamic performance of the I λ DN-T controller and several well-known controllers, including the integral filtered derivative-tilt (IDN-T), tilt-integral-derivative (TID), and conventional proportional-integral-derivative (PID) controllers. Additionally, the impact and integration of hybrid renewable energy systems (wind: 70 MW and solar: 50 MW) for area 1 and area 2 is investigate. The dynamic analysis reveals that I λ DN-T controller significantly outperforms the others in terms of key transient parameters such as overshoot, undershoot, and settling time. Furthermore, a sensitivity analysis demonstrates the robustness of the SSA-tuned I λ DN-T controller under varying system parameters and dynamic loading conditions. The stability margin results confirm the feasibility and effectiveness of the proposed I λ DN-T controller in frequency regulation of hybrid power systems, highlighting its robustness and excellent dynamic performance under perturbed operating scenarios. Lastly, the experimental result from real-time OPAL-RT setup confirms the practicality of the proposed control system.