Ventilation and Thermal Improvement of Radial Forced Air-Cooled FSCW Permanent Magnet Synchronous Wind Generators

This paper presents coupled fluid-thermal analyses to improve the ventilation and thermal performance of radial forced air-cooled fractional-slot concentrated-winding (FSCW) permanent magnet synchronous wind generators (PMSWGs) using the computational fluid dynamics (CFD) method. Three-dimensional coupled fluid-thermal CFD models are established based on the governing conservation equations of the solved solid machine parts and the air domain. The losses are applied into the CFD models as the heat sources and the boundary conditions are determined. Based on the proposed method, the fluid and temperature field of the machines with different air cooling channel numbers and channel widths are calculated, and the ventilation and thermal performance are compared to determine the optimal channel number. Further, an alternative cooling structure with radial winding holes through the slot center to dissipate heat from the winding directly is proposed. The results show that it is a promising alternate, especially for the FSCW PMSWGs to decrease the winding temperature and ventilation losses. The proposed CFD method is validated by experiments implemented on a standard product of integral-slot distributed-winding (ISDW) PMSWGs with the same ventilation system.