Robust Decentralized Load-Frequency-Control of Multi-Area Power Systems with RES and HVDC: A Composite PIλ1D-PIλ2DF and Fuzzy-PID Approach

The operational stability of modern interconnected power systems globally is increasingly challenged by inherent parametric uncertainties and nonlinearities, leading to significant deviations from nominal system frequency (50Hz or 60Hz). The problem is further complicated by the escalating incorporation of intermittent renewables, including wind and solar power, leading to a notable reduction in system inertia and impaired frequency regulation. To mitigate these adverse effects, this study introduces a novel control strategy: an Improved Grey Wolf Optimization (iGWO)-tuned Fuzzy-PID controller integrated with a PIλ1D-PIλ2DF model. This strategy is tailored to achieve frequency stabilization within a multifaceted four-area interconnected electrical network. A key contribution of this work is its explicit modeling of intricate system dynamics, including nonlinear characteristics, HVDC (High-Voltage Direct Current) transmission interconnections, and wind energy generation dynamics. The proposed control strategy's effectiveness and superiority are rigorously validated through comparative simulations under various load change scenarios, contrasting its performance against conventional GWO-tuned PID and standard PID controllers. These comparisons highlight the significant strengths of the iGWO-optimized Fuzzy-PID controller in addressing the complex challenges inherent in contemporary interconnected power systems.