Piezoelectric plate generator from consecutive periodic rotary magnetic excitations

Abstract

The piezoelectric device, connected to the circuit interface and subjected to the consecutive periodic rotary magnetic excitations, is presented for an energy harvesting application. The proposed system consists of a cantilevered piezoelectric plate structure with multiple attached magnets, along with a revolving disc carrying a single magnet. This study sets out to explore the primary development of explicit analytical and finite element formulations that consider magnetic coupling and time-delayed magnetic response. The two theoretical models are used to formulate the optimal power output frequency response equations using Fourier analysis. Due to the asymmetrical magnet locations and time-delayed magnetic response, the consecutive dynamic excitations periodically occur, resulting in dipole–dipole interactions in both spatial and temporal conditions. Consequently, the piezoelectric plate structure, designed to operate higher vibration modes, exhibits a predominant effect of frequency up-converting energy harvesters. The previous work is initially validated by using a single magnetic excitation and examining both cases with and without time-delayed magnetic responses. The analyses of broadband optimal power generations are based on Fourier’s harmonic numbers and frequency domains, including time-tracking magnetic excitations. Finally, various case studies are presented to examine the effects of different physical components, such as magnet numbers, magnet locations and masses, piezoelectric materials and thicknesses, and locations of electrode segments.