Design Analysis and Dynamic Measurement of a Novel Piezoelectric Energy Harvester Driven by Magnetic Force

Abstract

Based on the frequency up-conversion a novel PEH composed of a piezoelectric cantilever beam and plural magnets is proposed The output voltage and power can be analyzed and predicted by mathematical models including 3D magnetic force model and dynamic model derived from the piezoelectricity and vibration theory The model is validated by the finite element analysis and experiments In the experiment regarding to the magnetic force measurement the results show that the 3D force model provides more accurate magnetic force calculation for large distance between two magnets In addition the tilt angle of the magnet has a little effect of 7% difference from the case of no tilt angle indicating that the tilt angle can be neglected in the dynamic model The magnetic force distribution is imported into ANSYS a finite element analysis software to compute the transient responses of the PEH The natural frequency of the beam determined by the mathematical model has a 8 63% difference lower than that observed by experiments However the overall trend of the responses can be obtained from the mathematical model By the mathematical model the PEH can harvest a power of 0 645 mJ under an optimum load of 10 k? In the experiments of connecting an LED to the PEH a pulse current with a peak power of 774 ?W is observed which is sufficient to lighten the LED After validating the mathematical model it is used to investigate the optimization of some geometric parameters such as the size of the cantilever and the gap between magnets The results are helpful for improvements to the PEH design in the future

Date of Award	2019
Original language	English
Supervisor	Chung-De Chen (Supervisor)