Practical Considerations in the Design and Manufacture of Ultra-High Speed Switched Reluctance Machines Over 1 Million rpm

Abstract

High-speed switched reluctance machines (SRMs) are gaining in popularity recently in both industry and academia. For ultra-high speeds over 1 million rpm, many issues that seem to be trivial or even not realized at regular speeds are actually the key to the final success of the design. In this paper, the practical considerations identified during the design and manufacture of a 1 million rpm SRM are presented. Firstly, various issues in the manufacturing of the shaft and rotor are described in detail. Three prototypes with different features are built, showing the problems and feasibility of the design. Then, the practical design and manufacturing considerations of the whole assembly of a prototype 1 million rpm SRM are presented. These include issues regarding the stator & windings, the bearing housings, face collars, sensor tables, final assembly and alignment. Finally, the expected challenges of estimation and measurement of the torque and losses of the machine at ultra-high speeds are discussed.