Comparison of different Surface Mounted Permanent Magnet patterns

This paper investigates how to improve the compactness of a Synchronous Permanent Magnet Surface Mounted machine for high-frequency and high torque direct-drive applications. For that, the performances such as power mass density and losses of different pole patterns, e.g. Halbach and conventional radial magnetized magnet arrays are compared. Depending on the given specifications, some considerations concerning the decision-making process, taking into account process and assembly constraints when choosing between the conventional radial magnetization and the Halbach array, are reported.