Offshore wind blackstart & restoration: state-of-the-art literature review

As Power Systems decarbonise, Offshore Wind Power Plants (OWPPs) are increasingly considered as replacements for conventional Blackstart units. This work synthesisesState-of-the-ArtOWPP blackstart capabilities, whose Wind Turbine Generators (WTGs)—upgraded with Grid-Forming (GFM) controls in their Voltage-Source (Power-Electronic) Converters (VSCs)—establish and regulate island voltage and frequency, energise networks, and resynchronise. Traditional Restoration guidelines centre on Synchronous Generators, yet emerging codes expect converter-interfaced resources to assume these roles. Electromagnetic Transient (EMT) studies and pilot tests demonstrate that a limited number of GFM WTGs can energise AC cables, transformers, and High-Voltage DC (HVDC) terminals when sequencing, protection, and control are co-designed. From the modelling point of view, this literature-based work pinpoints six research gaps: (1) re-energisation sequencing of the dead system; (2) WTG/OWPP model fidelity and data confidence; (3) low-fault-current and protection coordination; (4) GFM controls suitable for blackstart operations; (5) multi-converter operation across mixed GFM/GFL WTG units plus HVDC/Battery Energy Storage Systems (BESS); and (6) resynchronisation with load pickup and transition to normal operation. The analysis concludes that GFM-controlled OWPPs remain promising yet under-demonstrated, and consolidates fragmented results into guidance and a set of focused, actionable guidelines to help certify OWPPs as reliable blackstart resources.