Torque analysis using geometrical interpretation of the Stieltjes integral

This paper presents a method for torque calculation based on a geometrical interpretation of the Stieltjes integral, which can be interpreted as the geometrical area of a (B,H) plot for the magnet used in the rotor, with the circumferential coordinate (angle) as the running parameter. The available maximum torque is discussed for a SPM type and a Halbach-arrayed configuration, followed by its confirmation and elaboration using FEM computation results.