Design, analysis, and manufacturing of low-power high-speed synchronous generators

Abstract

High-speed electrical machines are vital components in modern engineering systems, offering significant advantages in performance, efficiency, and compactness. Their ability to operate at elevated rotational speeds enables faster processing, reduced system size, and improved power density, making them indispensable in applications such as aerospace, automotive, industrial automation, and renewable energy systems. Advances in materials, cooling techniques, and power electronics have further expanded their capabilities, allowing for reliable operation under demanding conditions. As industries continue to prioritize speed, precision, and sustainability, high-speed machinery is poised to play a central role in the next generation of high-performance electromechanical systems.

The first section of this doctoral dissertation focuses on establishing parameters for lowpower, high-speed synchronous generator design under auxiliary power unit specifications for non-road mobile machinery (NRMM). The subsequent section addresses the selection, conceptualization, evaluation, optimization, and manufacturing of high-speed generators. Two high-speed (100 krpm) small-size generator designs are considered for comparison and study. Both generators use a unique type of drum winding structure that supports the high-speed dynamic model of the rotor, providing a compact structure for NRMM. This kind of winding arrangement can also aid in the cooling of the machine. One of the generators has a permanent magnet rotor, whereas the other rotor contains no rare earth metals but can nevertheless produce electricity at a high efficiency and speed comparable with the rare-earth-metal-based generator. An analysis of the rotor components of the generators is conducted to verify the mechanical integrity of the rotor. Following the modification of the rotor characteristics, they are employed to finalize the electromagnetic model of the generator, which covers the design of the stator, slot wedges, and the influence of laser cutting on the electromagnetic characteristics of the stator core. A probability density function is employed to demonstrate the effect of varying thermal coefficients and the temperatures of the input and output cooling fluids on the output temperature of the machine, utilizing the 3D structure of the machine. Finally, the different parts of the machines are fabricated, and the practical problems related to the machine fabrication are shown. Both machines will be subjected to further evaluation and testing in subsequent phases of the research, which requires the addition and evaluation of a cooling arrangement and a drive system. A plan for the research valorization of the axially laminated synchronous reluctance machine (ALAsynRM) is also in progress.