Modelling of a cantilevered energy harvester with partial piezoelectric coverage and shunted to practical interface circuits

Abstract

This article presents a modelling methodology for a cantilevered energy harvester with partial piezoelectric coverage and shunted to practical power conditioning interface circuits. First, the distributed parameter model of the partially covered piezoelectric energy harvester is developed and the associated analytical solution is derived. Subsequently, the single-degree-of-freedom representation model is developed and the explicit expressions of equivalent lumped parameters are derived by taking the static deflection as the approximated fundamental vibration mode. Based on the comparison with the single-mode expression of the distributed parameter model, a correction factor is proposed to improve the accuracy of the single-degree-of-freedom model. The results of both the distributed parameter and the corrected single-degree-of-freedom models are compared. The accuracy of the corrected single-degree-of-freedom representation model is verified against the analytical and the finite element models. Finally, practical interface circuits including the standard energy harvesting circuit and the parallel synchronized switch harvesting on inductor circuit are considered. A modified equivalent impedance modelling method is proposed for the analysis of the standard energy harvesting and parallel synchronized switch harvesting on inductor circuits. The results of the modified equivalent impedance modelling method are verified against the existing method in the literature.