A modular and cost-effective high-temperature superconducting generator for large direct-drive wind turbines

Abstract

High temperature superconductors (HTS) enable very compact electric machines with high power density. The aim of this paper is to study and improve an HTS power generator based on the authors' previous 10 MW double claw pole design. An additional stator was added to the machine, increasing the copper volume in the generator, resulting in a large increase in power density. Furthermore, with the additional inner stator, the overall current density in the individual stators can be reduced, leading to an increase in efficiency. The modularity of the generator is further improved through the addition of the third stator, further increasing its fault tolerance. The efficiency of the machine can be increased from 94.5% to 95% at a power output of 11.5 MW or through a further reduction of the current density in the stators, an efficiency of 95.6% can be reached while maintaining a power output of 10 MW. Hence, the newly proposed design offers a potential increase in power density, efficiency and modularity while maintaining the same machine diameter and low HTS tape requirements, making the design a very cost-effective option to enable 10 MW direct-drive wind turbines.