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Due to the increasing demand for electrification in the automotive sector, the interest in the manufacturing and processing of pure Copper (Cu; purity 99.99%) is also increasing. Laser-based technologies have proven to be challenging due to Cu's high optical reflectivity. Processing pure Cu with Electron Beam Melting (EBM) is a promising manufacturing route, allowing for high design freedom. The highest priority is to achieve outstanding thermal and electric conductivity in manufactured Cu components. Chemical contamination or manufacturing defects, such as porosity, significantly reduce the thermal and electric conductivity. The literature on post-processing (thermal and abrasive) of additively manufactured Cu is scarce. Therefore, this study discusses the correlation between as built and heat treated microstructure, as well as surface roughness on the EBM electric conductivity. EBSD analysis is performed to analyze the effect of microstructure on electric conductivity. The effect of sandblasting and vibratory finishing on surface roughness and electric conductivity is investigated. Additionally, the samples are mechanically tested in terms of hardness. [ABSTRACT FROM AUTHOR]

In this paper a description and operating principles of a consequent-pole permanent-magnet machine are presented. In addition, a sizing analysis, finite-element analysis, and experimental results for a prototype machine are addressed. Due to its particular configuration, this machine allows for a wide range of control of the air-gap flux with minimum field ampere-turn requirements and without brushes or slip rings. Two components of the field flux are produced. One, which is almost constant, is produced by the permanent magnet located on the rotor surface. The other, which is variable, is produced by a field winding positioned circumferentially in the center of the stator. These two flux components converge in the air gap. The excitation level of the machine is manipulated by controlling the dc field current. Three-dimensional finite-element analysis and experimental results demonstrate that it is possible to vary the flux over a wide range to keep the terminal voltage constant as the speed increases. A 3-kW 1000-3000-r/min eight-pole and 32-Vac generator using this configuration is tested to verify the flux control capability of this structure. Index Terms--Electric machine design, flux weakening, permanent-magnet (PM) machine.

Based on the concept of the converter fed machine (CFM), an optimal machine design can be considered as the best match of the machine topology, the power electronic converter and the performance specification. To compare power production potential of axial flux machines with various topologies, different waveforms of back emf and current, general purpose sizing and power density equations for such machines are needed. In this paper, a general approach is presented to develop and to interpret these equations. Sample applications of the sizing and power density equations are utilized to compare the axial flux toroidal permanent magnet (AFTPM) machine and the axial flux two-stator permanent magnet (AF2SPM) machine.

Whenever an electrical machine is meant to be fed by a power converter, the design should be approached as a system optimization, more than a simple machine sizing. A great variety of electrical machines is available to accomplish this goal, and the task of comparing the different options can be very difficult. A general purpose sizing equation, easily adjustable for every topology, that could take into account different waveforms and machine characteristics, would be a very desirable tool. In this paper, a general approach is presented to develop and to discuss such an equation. Sample applications of the sizing and power density equations are utilized to compare the induction machine and the doubly salient permanent magnet (DSPM) machine. Index Terms - Ferrites, magnets, motors, power density, sizing equation.

This paper presents a soft-switched ac/dc converter structure, useful for current-fed inverters and forced-commutated PWM rectifiers with inductive load. Typical applications are high-power ac motor drives, magnet power supplies and active power filters with inductive energy storage. As compared to hard-switched converters, the proposed solution calls for some increase of the circuit complexity, but provides improved input and output performances due to the higher switching frequency. Further improvements are ensured by proper control of the commutation process. Actual converter capabilities are demonstrated by experimental results.

This paper presents the calculated and the measured performance capability of a cage rotor induction machine used as a direct connected, crankshaft speed, combined starter--alternator for an automotive diesel engine in an experimental hybrid electric vehicle. The calculated results are based on a nonlinear equivalent circuit model of the machine in which saturation is considered only in the stator and rotor magnetizing flux paths. The development details of this model are given as well as several sets of calculation results for a prototype induction machine. Finally, measured maximum performance results for the test machine are presented and compared with model-based calculated results for the same operating conditions of speed, terminal voltage, and current. Index Terms--Induction motor model, starter--generator.