Opportunities and Challenges in the Mediterranean Region with Grid Forming Control for HVDC Systems

The progressive displacement of conventional generation towards renewable energy sources requires restoring an adequate capacity of regulating power to ensure reliable operation of power systems. Power systems with large shares of converter-interfaced renewables are characterized by low grid inertia due to the lack of frequency containment provided by synchronous generators. High Voltage Direct Current (HVDC) Transmission Systems based on Voltage Source Converter (VSC) technology are considered valuable assets to improve frequency regulation capacity levels. HVDC converter stations based on VSC technology are typically able to operate in either grid forming or grid-following modes. The aim of this paper is to highlight the opportunities and challenges of grid forming control for HVDC applications. A special focus will be on contradictory grid forming control performance requirements from European Transmission System Operators (TSOs). The impacts of these requirements on AC grid, HVDC performance and hardware are discussed.