Radial Flux Leakage Integrated Quasi-3D Approach for Accurate Axial Flux PM Motor Analysis

Axial flux permanent magnet (AFPM) motors have drawn significant attention due to their compact size, high torque density, and broad applicability. However, accurately designing an AFPM motor requires computationally intensive three-dimensional finite element analysis (3D FEA) owing to its topology. To alleviate this, a quasi-three-dimensional (quasi-3D) model can be employed, in which the AFPM motor’s geometry is divided in the radial direction and represented in a flattened, two-dimensional equivalent form. The quasi-3D model offers an efficient alternative, but it typically fails to consider important factors, such as radial flux leakage. This limitation can result in discrepancies between the predicted voltage and torque and those obtained from 3D FEA results. In this article, we improve the conventional quasi-3D model by calculating the radial leakage path’s permeance and incorporating it into the two-dimensional analysis. As a result, the improved quasi-3D model exhibits a better correlation with 3D FEA than the conventional quasi-3D model with a higher division. The improved quasi-3D model significantly reduces computational cost with minimal sacrifice of precision compared to 3D FEA, enabling faster and more reliable design processes.