DC Offshore Wind Farms to Support Grid Restoration

Abstract:
In the event of a blackout, grid restoration is essential for resuming normal operation. This process depends on black start capable units that can independently energize the grid without external power. This paper introduces a novel black start concept for an offshore wind farm with a DC collector grid. The concept, including allowed voltage levels, an operating plan, and a definition of requirements, is validated through a numerical electromagnetic transient simulation. This simulation illustrates the grid restoration process within an offshore DC wind farm following a total blackout and the provision of black start power to the main grid. It encompasses the wind farm’s mechanical, electrical, and control systems. Furthermore, the annual availability is evaluated using measurement data. This research demonstrates the advantages of DC systems in simplifying the electrical synchronization of multiple wind turbines and highlights the potential of renewable energy sources in critical restoration scenarios, including the feasibility of islanded operation of the wind farm as an islanded DC microgrid.