A Detailed Thermal Analysis for Performance Improvement of Axial Transverse-Flux-Switching PM Wind Turbine Generator

Abstract

The efficiency of energy conversion from mechanical to electrical in AC generators is not entirely optimal, as power losses are converted into heat. Accurate thermal modeling and temperature measurement of advanced electric machines with complex structures are mandatory to confirm their reliability and safe operation. In a unique axial transverse flux switching permanent magnet (ATFSPM) generator, due to its high power density, large stray loss from leakage flux, compact topology, and totally enclosed structure, thermal analysis is of paramount significance. In this paper, thermal modeling and analysis of ATFSPM are carried out in detail using a three-dimensional (3D) finite element analysis (FEA) to evaluate the thermal condition for a precise performance improvement. To begin, all loss sources are accurately derived using 3-D FEA and analytical methods, taking into account the temperature dependence of material properties, and then losses are coupled to the thermal model as heat sources. Afterward, aiming for realistic thermal modelling, the convection heat transfer in the different regions of internal and external areas as well as thin layers of interface gaps between components are all considered. In addition, the prototype of ATFSPM is supplied to validate the accuracy of 3-D FEA temperature prediction. Furthermore, a novel technique is carried out to effectively improve thermal performance, enhance the efficiency, and limit hot-spot temperatures. The steady-state and transient temperature results demonstrate the high accuracy of the thermal modeling, enhance the secure operation of the ATFSPM, and facilitate increased loading utilizing the proposed technique.