Axial flux permanent magnet machines for direct drive applications

Abstract

This thesis explores aspects of the design, analysis, and experimental test of permanent magnet axial flux machines for use in diesel engine generator sets, vertical axis wind turbines, and wheel motors for solar cars. The characteristic geometry of axial flux machines is naturally more suitable than that of conventional topologies in certain applications. However, convenient and accurate methods of electromagnetic design and analysis are less well established for such machines. The purpose of the research described herein is to benchmark a range of methods of analysis which can be extended to novel designs. There is a particular focus on the use of Finite Element Analysis to facilitate greater understanding of these machines through the illustration and quantification of the electromagnetic aspects of their operation, and the verification of a selection of analytical approaches. Prototype TORUS machines are first considered; the various analyses are then extended to iron-cored axial flux machines having slotted conductors and finally to a selection of novel machines having concentrated coils and an ironless stator. The analyses are successfully extended to a range of machines, and the particular suitability of axial flux permanent magnet machines in certain direct drive applications is demonstrated.