Design of High-Power Ultra-High-Speed Rotor for Portable Mechanical Antenna Drives

Abstract

This article presents the design of high-power ultra-high-speed (HP-UHS) rotors of permanent magnet machines for a mechanical-based ultra-very low frequency (ULF-VLF) antenna (AMEBA) application. The conventional communication system in an RF-denied environment (e.g., underground and under seawater facilities) is power demanding with very low efficiency and low power density. Thus, a portable communication system was not available until recently. Such a critical limitation could be overcome by utilizing an HP-UHS motor as a mechanical communication transmitter. This is a first attempt to the best of the authors’ knowledge. However, the unprecedentedly high-speed and HP AMEBA exhibits new design challenges, including the critical mechanical resonance of the rotor, coupled with wireless communication bandwidth (ULF-VLF). It limits the highest possible efficiency and power density of portable AMEBA systems while achieving a required design safety margin (DSM). In this article, such critical constraints of HP-UHS rotors are analytically derived and integrated into a design model. This new design model will effectively couple the electromagnetic, thermal, structural, and rotordynamic analyses for the successful AMEBA rotor design. In the optimization, the Kriging method is adopted to create the efficient approximation model of the design nonlinearities. Multiple objectives and Pareto-front analysis are used to obtain an efficient rotor design with high DSM. The proposed approach is applied to design a 2-kW 500 000 r/min rotor considering AMEBA requirements. The effectiveness of the rotor for the AMEBA application has been validated through 3-D finite-element analysis and experimental testing.