An ultra-compact lightweight electromagnetic generator enhanced with Halbach magnet array and printed triphase windings

Abstract

Electromagnetic generator (EMG) plays a pivotal role in in-situ power supply for low-power electronics. However, a major challenge associated with EMGs is the limited power density. To address this issue, various strategies have been proposed, including magnetic field augmentation of magnets, magnetic flux variation rate escalation at the coil, and structural miniaturization. In this study, we present an innovative ultra-compact electromagnetic generator (UL-EMG) in light weight that integrates the Halbach magnet arrays and printed circuit board (PCB) technologies. The UL-EMG incorporates a 12-layer printed triphase windings into its PCB stator, thereby upgrading both device compactness and output performance. To assess the performance of the UL-EMG, comprehensive bench tests were conducted. Interestingly, results indicate that at a low rotational speed of 200 rpm, the UL-EMG achieved a peak AC output power and power density of 54.9 mW and 1.25 kW/m3, respectively, representing a 22-fold expansion compared to conventional EMGs. Moreover, the UL-EMG exhibited exceptional output characteristics across a wide range of rotational speeds, significantly bolstering its capacity to drive various low-power electrical appliances. This study paves a novel path for heightening the power density of EMGs and highlights the promising application prospects of compact EMGs in in-situ power supply advancement.