Mechanical and Thermal Analysis of a 5MW Double-Stator Single-Rotor PMSG for Direct Offshore Wind Turbines

This Thanks to the higher power density, the Double-Stator Single-Rotor (DSSR) Permanent Magnet Synchronous Generator (PMSG) is considered one of the solutions to the challenges, i.e., heavy weight and large size, in the traditional PMSGs for direct-drive offshore wind turbines, whose power rating is ever increasing. However, the unique structure of the DSSR PMSG may raise such reliability concerns as their mechanical stress and thermal dissipation. In this work, a 5 MW DSSR PMSG is optimally designed first. Then the extent of deformation in the air gap is analyzed using Finite Element Analysis (FEA). Moreover, different frames to support the generator structure are examined, which helps to limit deformation in the air gap to permissible values. Furthermore, thermal analysis of the generator is done using FEA to ensure adequate cooling of permanent magnets and copper under full load. The comprehensive analysis shows that the DSSR PMSG with a proper design can serve as a feasible topology for the direct-drive PMSGs for offshore wind turbines.