With increased need for high power density, high efficiency and high temperature capabilities in aerospace and automotive applications, integrated motor drives (IMD) offers a potential solution. However, close physical integration of the converter and the machine may also lead to an increase in components temperature. This requires careful mechanical, structural and thermal analysis; and design of the IMD system. This study reviews existing IMD technologies and their thermal effects on the IMD system. The effects of the power electronics position on the IMD system and its respective thermal management concepts are also investigated. The challenges faced in designing and manufacturing of an IMD along with the mechanical and structural impacts of close physical integration is also discussed and potential solutions are provided. Potential converter topologies for an IMD like the matrix converter, two-level bridge, three-level neutral point clamped and multiphase full bridge converters are also reviewed. Wide band gap devices like silicon carbide and gallium nitride and their packaging in power modules for IMDs are also discussed. Power modules components and packaging technologies are also presented.

Abstract-This paper describes the design process of a 10 kW 19000 rpm high power density surface mounted permanent magnet synchronous machine for a directly coupled pump application. In order to meet the required specifications, a compact machine, with cooling channels inside the slots and flooded airgap, has been designed through finite element optimization. For high power density, high speed machines, an accurate evaluation of the power losses and the electromechanical performance is always extremely challenging. In this case, the completely flooded application adds to the general complexity. Therefore this paper deals with a detailed losses analysis (copper, core, eddy current and mechanical losses) considering several operating conditions. The experimental measurements of AC copper losses as well as the material properties (BH curve and specific core losses), including the manufacturing process effect on the stator core, are presented. Accurate 3D finite element models and computational fluid dynamics analysis have been used to determine the eddy current losses in the rotor and windage losses respectively. Based on these detailed analysis, the no load and full load performance are evaluated. The experimental results, on the manufactured prototype, are finally presented to validate the machine design.Index Terms-High power density, high speed, losses calculation, performance analysis, permanent magnet motors.

Abstract-Synchronous reluctance machines, including the permanent magnet assisted variants are competitive motor topologies if the application requires high efficiency and a cost effective solution with a high flux weakening capability. However, increasing operating speeds incur challenging design and development decisions, mainly in order to find design solutions that ensure the machines structural integrity without compromising the overall performance. In this paper, a comprehensive design procedure for high speed synchronous reluctance machines is presented. In order to validate the procedure, a 5 kW, 80000 rpm machine is considered. The proposed strategy consists of a two-step procedure in which the electromagnetic and structural designs have been properly decoupled dividing the design space in two subsets. Each subset mainly affects the electromagnetic or the structural performances. Several structural design optimizations have been then performed with the aim of finding the optimal trade-off between the rotor geometrical complexity (that defines the required computational resources) and the electromagnetic performance. The reported experimental tests of the prototyped machine validate the proposed design strategy which can be used as general guidelines on the structural design of synchronous reluctance machines.

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