Advanced Metaheuristic Techniques for Optimal Operation of Multi-Terminal HVDC Grids

The need for efficient long-distance power transmission has accelerated the development of multi-terminal high voltage direct current (MT-DC) systems. This study presents an advanced control strategy for optimizing the performance of voltage source converters (VSCs) in MT-DC grids by employing an hybrid grey wolf optimization-particle swarm optimization (GWO-PSO) technique. The proposed control framework consists of an inner and outer control layer, where the inner layer regulates converter current, and the outer layer manages power flow, voltage stability using a proportional-integral (PI) controller. Therefore, tuning of PI controllers is optimized to improve system response, reduce power deviations, and enhance overall grid stability. Simulations performed on MATLAB show that hybrid GWO-PSO optimized control outperforms conventional PI tuning methods, significantly reducing power fluctuations and improving dynamic response in both wind farm and ac grid stations.