Multi-Objective Optimization of a Direct-Drive Wind Turbine Generator With HTS Excitation Winding

Steadily increasing rated unit power of direct-drive wind turbine generators for offshore applications requires solutions with high torque density. HTS excitation windings allow for a higher electromagnetic utilisation compared to an excitation by rare-earth permanent magnets but must be competitive regarding overall cost. This work addresses this multi-objective optimisation problem (mass, cost) by means of a numerical evaluation for a generator design with conventional iron parts and HTS excitation winding under variation of eight variables. The
Pareto
frontier is approximated for HTS excited direct-drive generators in the 7 MW power class.