Rapid designing of Permanent Magnet Synchronous Machines (PMSM)

The dimensioning of electrical machines remains an essential step in the design of an electromechanical device. The computing power and numerical analysis precision of today's computers, as well as the visual quality of the work interface under specific software, can never replace the analytical approach to determining the geometric and electromagnetic parameters of an electrical machine. This analytical approach is based on two possible approaches: the vector potential calculation or the reluctance network.

The vector potential method is the basis of electromagnetism. Its theory was demonstrated by James Clerk MAXWELL over 150 years ago. All numerical approaches and finite element analysis software are based on this type of calculation. Despite its precision, the vector potential calculation remains an analytical dimensioning method used exclusively by specialists, with very long mathematical expressions, very complex calculation of integration coefficients where the risk of calculation error is very high, and for which the possibility of simplification and adaptation to similar structures is very difficult (sometimes impossible).

The reluctance (or permeance) network is the classic method in electrical engineering for calculating and characterizing magnetic circuits. This approach is based on many simplifying methods, and some parameters are adjusted empirically. However, for a more detailed calculation, iterative calculations can be added (the saturation calculation, for example). As a method that does not require sophisticated analytical calculations, this approach is useful for estimating the overall performance of electromechanical drive devices, and is therefore preferred by industrial designers.

The present work is proposed for the industrial environment as a rapid sizing tool for electrical machines, in particular for electromechanical devices excited by permanent magnets. There are various approaches to dimensioning. The proposed method is based on reluctance network calculations, to which coefficients obtained numerically (using finite elements) or by measurement are added. The aim is to present a comprehensive, easy-to-implement analytical approach for sizing permanent magnet synchronous machine (PMSM) structures.

In an introductory section, we present a few generalities on MSAPs and their constituent elements (magnet operating point, different types of winding depending on a given application, usual rotor structures excited by permanent magnets). A comprehensive approach to the rapid dimensioning of MSAPs is then presented (with several rotor topologies, their geometric and electromagnetic parameters, operating characteristics). Procedures for determining other sizing parameters enable thermal, mechanical...