Influence of electrical steel grade on the temperature distribution in direct-drive PM synchronous generators for 5 MW wind turbines

Abstract

The effect of the magnetic and thermal properties of 4 electrical steel grades were compared for a Permanent Magnet Synchronous Generator (PMSG). The low loss grades are expected to have less iron loss in the stator lamination, but their thermal conductivity may be lower. Therefore, the evacuation of the heat may be less effective. This has an influence on the temperature distribution, which is crucial in case of PMSG. The investigated generator is a 5 MW, radial flux machine designed for direct drive wind turbines. A thermal Finite Element Model was used to simulate the temperature distribution in the generator. The influence of the steel grade on the thermal distribution was compared for three geometries of PMSG with air gap diameter equal to 4, 6 and 8 meters respectively. In conclusion, for all three geometries, the thermal distribution is not dependent on the electrical properties, but mainly on the thermal conductivity of the steel

Thermal Model of Totally Enclosed Water-Cooled Permanent-Magnet Synchronous Machines for Electric Vehicle Application

“…In [27], Kowal et al investigated the relationship between the thermal conductivity of materials and their electromagneticthermal performance and demonstrated that the thermal conductivity of steel has an influence on the temperature distribution. In order to reasonably simplify the thermal analysis, it is assumed that different heat sources (losses) are distributed uniformly in the corresponding heating elements and the calculated thermal nodes is located at the centre of the heat elements.…”

Thermal model of totally enclosed water-cooled permanent magnet synchronous machines for electric vehicle applications

“…In [27], Kowal et al investigated the relationship between the thermal conductivity of materials and electromagnetic-thermal performance and demonstrated that the thermal conductivity of steel has an influence on the temperature distribution. In order to simplify the thermal analysis reasonably, the assumption that different heat sources (losses) distribute in the corresponding heating elements uniformly and the calculated thermal nodes locates at the centre of heat elements.…”