On the investigation of the magnetic forces of CWPMM

Purpose – The purpose of this paper is to investigate the magnetic forces generated by a 12 slot/10 pole concentrated winding PM machines, considering a comparative study between two topologies: a surface mounted permanent magnet (SPM) machine and an interior PM (IPM) machine. Design/methodology/approach – Following a description of the main characteristics of the concentrated winding permanent magnet machines (CWPMMs) under comparison, an investigation of the magnetic forces developed by both machines under study is carried out using finite element analysis (FEA). Findings – A 2D FEA-based investigation has highlighted that the SPM machine develops higher magnetic forces than the IPM one. However, and following a 3D FEA, it has been found that the distribution of the magnetic forces along the air gap of the SPM machine is almost homogenous while it is concentrated in two opposite positions in the air gap of the IPM machine. Research limitations/implications – This work has treated almost all features of the machines under comparison, except the power losses. These should be investigated with emphasis on the PM eddy current losses is so far as the harmonic content of the armature air gap MMF is high. Practical implications – The list of the selection criteria of CWPMMs should be extended to the magnetic force cancellation in order to fulfill the requirements of many applications such as the automotive ones. Originality/value – The paper proposes a combined electromagnetic-mechanical approach to investigate the magnetic forces generated by CWPMMs using 2D and 3D FEA.