Torque calculation method for axial-flux electrical machines in finite element analysis

Abstract

Rotating electrical machines are becoming ubiquitous as we move towards a more electrified and sustainable world. Torque calculation is an essential task in the design process of rotating machines. In the frame of finite element analysis, the Maxwell stress tensor method is a common technique to calculate the torque exerted on a rigid body. However, the computed torque is strongly mesh-dependent and can be inaccurate. The popular Arkkio method can overcome this problem. But Arkkio's formulation can only calculate the axial torque of conventional radial-flux electrical machines and is unsuitable for axial-flux motors and generators, which are attracting increasing interest due to the power density and efficiency improvements that the axial topology can enable. This article presents an easy-to-implement formulation for calculating the axial torque of axial-flux machines in finite element analysis.