Active Ballasting Actuation for the SpiderFLOAT Offshore Wind Turbine Platform

A novel platform actuation technique is investigated for an offshore wind energy system, the Ultraflexible Smart FLoating Offshore Wind Turbine (USFLOWT). USFLOWT uses a novel floating substructure, SpiderFLOAT, designed to significantly reduce capital expenditure (CAPEX) of wind turbine system via modularized slender structures, efficient load paths, and cost-effective use of materials. The SpiderFLOAT includes three concrete legs with three sets of buoyancy cans. The cans can be actively ballasted to allow an efficient (low power consumption) change of the mean platform heel angle within a few minutes. Results showed that active ballasting adapts to thrust loads so the platform can be set in an ideal position of zero pitch angle under both rated operational conditions and parked extreme-load conditions. This actuation can help mitigate loading on critical components to ensure maximum power output at a given mean wind speed.