PM material selection guide for IPMSM

The aim of this paper is to provide a well-organized design procedure for selecting the proper permanent magnet (PM) material to be used in constructing the interior permanent magnet synchronous machines (IPMSM). A simple and clear design flow chart is introduced to support the machine designer in each design step. The design starts by selecting one of the proposed PM grades as a base line material. The flow chart provides a guide to the machine designer in selecting the proper volume for the selected material in order to provide the required power and torque. This is followed by optimizing the PM volume of the base line material. Finally, a comprehensive comparison between different PM material grades in terms of size, cost and ability to withstand the demagnetization. A case study is introduced to compare between different Neodymium-iron-boron (NdFeB) rare-earth magnets grades and samarium-cobalt (SmCo) magnets grades in order to describe and verify the proposed procedure. Applying the proposed selection guidance on the case study has shown fast and accepted results. A 2D finite element simulation using Motor-CAD software package driven by Matlab using the ActiveX has been scripted in the verification process for the case study. Pros and Cons of each material grade are discussed through the case study as well.