High-speed alternators are believed to be well developed nowadays, following the improvement in performance and decrease of costs for electronic power converters and permanent magnet materials. Their compact design and their ability to vary the rotational speed in off-design conditions promise superior performance when compared to conventional generators. High-speed alternators are only available in limited sizes for small-scale applications, whereas improvements in efficiency and optimized part-load behavior are particularly important especially for small-scale electricity generation.
Enhanced energy utilization for electricity production by small utility plants or by distributed units located at private homes or commercial buildings, based on thermodynamic cycles powered by natural gas or various renewable energy sources, is possible to be achieved through a wider application of grid-integrated high-speed technology. This study presents a critical review of previous research and demonstration work on high-speed electrical machines and a summary of the technical challenges limiting their performance and their expansion into larger sizes. Conclusions are drawn for finding appropriate solutions for practical high-speed electricity generation units and their readiness for a much wider deployment.
Closer analysis is attempted on the thermal and mechanical integrity of high-speed alternators and the technical challenges that slow down their scale-up to MW-size units for utility applications. The necessary research and development work that needs to be done in the near future is outlined and discussed herein.