Analysis and experiment of magnetic excitation cantilever-type piezoelectric energy harvesters for rotational motion

Abstract

Abstract In order to solve the problem that when the piezoelectric cantilever generator captures the low-frequency vibration, the structural resonance frequency bandwidth is small and the generating capacity cannot be fully developed. A magnetic excitation cantilever-type piezoelectric energy harvester for rotational motion was presented in this paper. Energy harvesting capability of resonant harvesting structures, such as piezoelectric cantilever beams, can be improved by utilizing coupled oscillations that generate favorable strain mode distribution. The theoretical analysis and simulation analysis of the working state of the piezoelectric energy harvester is performed. The power generation performance of magnetic excitation cantilever-type piezoelectric energy harvester under different environmental excitations was tested by experimental methods. The experimental results show that the magnetic excitation cantilever-type piezoelectric energy harvester has the best power generation performance when the rotational speed is 150 r min −1 , the installation angle of the piezoelectric cantilever is 60°, the distance between the mass magnet and the excitation magnet is 8 mm, and the number of excitation magnets is 6. The maximum open-circuit voltage of the magnetic excitation cantilever-type piezoelectric energy harvester is 38.49 V. When the load resistance is 40 KΩ, the magnetic excitation cantilever-type piezoelectric energy harvester has a voltage of 24.84 V and an average power of 15.425 mW. Piezoelectric energy harvesting is an attractive technique for the potential powering of wireless sensors and low power devices.