Sizing procedure of surface mounted PM machines for fast analytical evaluations

This paper presents a sizing procedure for the preliminary electromagnetic design of three-phase surface mounted permanent magnet machines having either inner or outer rotor structure. Starting from the requested rated data and few design specifications, the proposed approach consists on an iterative sizing procedure based on self-consistent equations. This sizing procedure is intended for those designers that, starting from scratch, have to define the main features of new machines for technical discussions and initial cost analysis for quotations. This analytical tool can also be easily integrated into sophisticated optimizers to manage the electromagnetic design and speed up the solution of high time-consuming multi-objective scenarios. To validate the proposed sizing approach, the paper reports as case studies the electromagnetic design of an inner rotor and an outer rotor surface mounted PM machine. The obtained results are validated both with an analytically-based commercial software dedicated to electrical machine analyses and with 2D FEM simulations.