HESS-Based Grid-Forming Black Start Strategy for Offshore Wind Farms Grid-Connection via MMC-HVDC

With the large-scale development of offshore wind power, MMC-HVDC transmission has become a mainstream grid integration solution due to its advantages of operational flexibility in long-distance power transfer. However, OWFs lack the inherent inertia and voltage support capabilities of traditional synchronous generators, making it difficult to autonomously restore power after grid failures (i.e., black start). The development of grid-forming control is regarded as a key technology to address this challenge due to their fast power response and energy buffering capabilities. This paper proposes a black start strategy for OFWs based on HESS GFM control, where HESS establishes AC voltage and cooperates with wind turbines to gradually restore the MMC-HVDC system with OWF integration. An integration model is developed in HYPERSIM to validate the performances of OWF LVRT and black start integrated with MMC-HVDC both in offline and real-time simulations.