Development of a natural cooled axial flux permanent magnet generator for wind turbine

Axial flux permanent magnet synchronous generators are of interest in power generation and traction application for its compactness and high power density these days. The high power density may cause thermal problem in this kind machine. Thermal design of a natural cooled machine was studied in this paper. The electromagnetic analysis was carried out by three dimensional finite element analysis (3D FEA) and the computation of thermal field is performed via a coupled thermal and fluid-dynamical model, where heat source was obtained from electromagnetic analysis. In order to enhance ventilation, the effect of blade installed at rotor was studied by computational fluid dynamic method. The prototype machine was built and thermal test was conducted at full-load generating operation.