Feasibility study of 5 MW superconducting wind turbine generator

The feasibility of installing a direct drive superconducting generator in the 5 MW reference offshore wind turbine of the National Renewable Energy Laboratory (NREL) has been examined. The engineering current densities J sub(e) obtained in a series of race track coils have been combined with magnetization measurements to estimate the properties of suitable field coils for a synchronous generator, which is more light weight than the conventional used combination of a gear box and a fast rotating generator. An analytical model and finite element simulations have been used to estimate the active mass of generators with varying number of poles. A 24 pole machine with an outer diameter of 4.2 m and active length and mass of 1.2 m and 34 tons is suggested possible, if a J sub(e) = 300 A/mm super(2) can be obtained in B = 4 T pointing to an operation temperature around 40 K.