Resistance Prediction of the Coil Pattern in a PCB Stator Axial Flux Permanent Magnet Synchronous Motor

Abstract

Axial flux permanent magnet synchronous motors (AFPMSMs) with a printed circuit board (PCB) stator offer advantages such as an ultra-thin and lightweight structure compared to conventional motors, enabling their use in various emerging applications. However, accurate estimation in AFPMSMs with PCB stators remains a challenge due to the nonuniform distribution of conductive areas, which can improve the efficiency. This paper presents a resistance prediction method based on Laplace equation and an equivalent circuit model, considering the geometric pattern and current path of PCB layout. The stator resistance is analytically derived using Laplace equation in the cylindrical coordinates. To implement the three-phase PCB stator, the via holes are employed to interconnect multiple layers, forming a complete electrical network. The resistance of each phase is determined by analyzing the electrical network. A 160W, 10 poles, three-phase AFPMSM with PCB stator is manufactured, and both finite element analysis and experimental measurements are performed to verify the proposed method. The effectiveness of the proposed method is validated through comparative analysis of the analytical results, FEA, and measured stator resistance.