Overview of Axial-Flux Machines and Modeling Methods

With the increasing requirements and demands for electric machines in various applications, axial-flux machines (AFMs) attract more and more attention in recent years because of their unique merits of high power density, compact structure, and high material utilization. This paper mainly investigates the topologies of AFMs and corresponding modeling methods. In general, AFMs can be classified according to different criteria. One classification is based on the machine configuration, and another one is based on their operational principles. The first classification discusses the characteristics of single-side AFMs, double-side AFMs, and multi-disc AFMs. The second classification discusses the characteristics of conventional AFMs and emerging AFMs. As for the modeling methods, this paper summarizes finite element methods and analytical methods in detail. Based on these investigations, the paper can provide the guidance and foresights for the design and analysis of AFMs.