Effect of Number of Phases on Losses in Conducting Sleeves of Surface PM Machine Rotors Equipped With Fractional-Slot Concentrated Windings

General Analytical Model of Magnet Average Eddy-Current Volume Losses for Comparison of Multiphase PM Machines With Concentrated Winding

“…The main problem with machines of fractional-slot concentrated winding is the existence of parasitic effects [3] which in certain cases might be unbearable because of unbalanced mechanical structure and/or high eddy-current magnet rotor losses [4]. Therefore, many researches have proposed a classification of this kind of machines in order to help the designer to avoid bad choice of Slots/Poles combination [5]- [6]- [7]. These classifications are mainly based on rotor global losses with and without copper cladding.…”

Design and Evaluation of a Multi-layer Interior PM Synchronous Motor for High-Speed Drive Applications

“…12(a). That is, in (8), there is no difference between their aerodynamic powers and it can be assumed that the shaft powers of both motors are almost identical. Thus, as System Eff.…”

“…As a result, the output of SPMSM is larger than that of IPMSM under 30,000 rpm but on the contrary the efficiency is lower. The reason is that except the losses dealt with in this paper additional eddy current losses generated in the sleeve and PM are much larger in the SPMSM [8][9][10]32]. However, as the load of blower increases in company with its speed, the efficiency of IPMSM is similar to that of SPMSM because in the IPMSM the influence of copper loss is dominant due to the rapid growth of input current to satisfy the required torque with its low back-EMF.…”

“…Next, manufacturing process such as shrink fit is added to assemble the sleeve on the PM. Finally, eddy current loss in the sleeve with electrical conductivity is generated by the slot or MMF harmonics [8][9][10]. Therefore, in this paper, a multi-layer interior permanent magnet synchronous motor (IPMSM) not using the sleeve is presented for high-speed applications.…”

Analytical model of magnet eddy-current volume losses in multi-phase PM machines with concentrated winding

“…The main problem with machines of fractional-slot concentrated winding is the existence of parasitic effects which in certain cases might be unbearable because of unbalanced mechanical structure or high eddy-current rotor losses. Therefore, many researches tried to classify this kind of machines in order to avoid bad choice of Slots/Poles combination [2]- [3].…”