Evaluating Renewable Energy Control Strategies Integrated with HVDC Droop Control for Sicily's Frequency Stability

High Voltage Direct Current (HVDC) tie lines can play a key role in maintaining system stability in interconnected power systems by modifying the power flows between areas to compensate for power imbalances. This study aims to evaluate the impact of the contribution of the HVDC converters of the West Tyrrhenian Link, connecting Sicily with Sardinia, to Sicily's primary frequency regulation in two different situations. Frequency deviation and the changes in power generation and flows are evaluated in case of losing the interconnection between Sicily and Calabria. Two mitigation measures are proposed to prevent instability due to the severity of the disturbance in the considered operating condition. The simulation results demonstrate that both proposed scenarios in conjunction with the regulation performed by the West Tyrrhenian Link HVDC converters are fundamental to maintain Sicily's frequency stability under this severe disturbance.