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This paper proposes a simple analytical machine sizing process for a three-phase surface mounted permanent magnet synchronous machines appropriate for both system level analysis and preliminary machine design. For system-level analysis, the proposed method can generate candidate machine models, be used to check if proposed performance values for a machine in a system level design problem are feasible or be integrated into a system-level optimization considering power electronics, passives, and machine. In machine design, the advantage of analytical process is it quickly generates candidate designs. These designs can be further refined using more computational intensive methods such as FEA, CFD, and machine design software.

Recently, the synchronous reluctance machine limits have been pushed toward meeting the requirements of traction applications. A skilled electromagnetic architecture of a synchronous reluctance machine with the help of permanent magnets can push the limits of power density and speed range to that of traction applications, however, the mechanical integrity of the rotor can still be in question. A traction application means large rotor diameter and high rotational speed, two criteria that makes a challenging design, in particular, mechanically. In this paper, the multi-physics design steps of a permanent magnets assisted synchronous reluctance motor for automotive application, have been presented. Firstly, the electromagnetic design following the size and thermal aspects and constrains has been conducted. Secondly, methods to reduce the mechanical stress has been explored and a bridged mechanical design has been adapted. Finally, thermal analysis of the machine has been conducted to ensure the thermal limits have been satisfied.

Computational Fluid Dynamics (CFD) was used to carry out a fluid flow and thermal investigation of a high power dense traction machine for electric commercial vehicle. One of the features of the machine design considered is the high Length/Diameter (L/D) ratio; this can represent a further challenge when performing the thermal design; indeed the heat dissipation from the stator core can represent an issue. The aim of this work is to identify an effective cooling configuration capable of enhancing the cooling of the stator and maintaining the operating temperature of the whole machine within the allowable limits. In this paper CFD analyses were therefore used to assess the thermal capability of several cooling arrangements; numerical results of each case are presented and compared. In particular an alternative cooling option, consisting in the implementation of heat pipes between the machine's stator teeth, was considered. Due to their simple structure and high heat transfer coefficients, heat pipes are not invasive but at the same time can dissipate large amount of heat. CFD results show how a significant temperature drop of the machine's core can be achieved.

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