Investigation of a d _(15) mode PZT-51 piezoelectric energy harvester with a series connection structure

摘要

A d _(15) mode piezoelectric energy harvester (PEH) with two PZT-51 elements in series connection (SC), in which the elements are arranged along the width direction, was fabricated, and it is compared with the traditional d _(15) mode PEH with a single PZT-51 element (SPEH) to discuss the output peak-to-peak voltage (U _(p-p)). The energy harvesting performances of PEHSC are modeled by combining the single degree of freedom model and the electrical model with the piezoelectric constitutive equation of the d _(15) mode. The energy harvesting performances of PEHSC were systematically measured at various frequencies and load resistances, and U _(p-p) and output power are 12.4V and 8.7μW at a load resistance of 2.2MΩ and resonance frequency of 73Hz. The experimental U _(p-p) of PEHSC and SPEH are 25.4 and 15.6V at the resonance frequencies under open circuit condition, and this indicates that the SC structure can improve the energy harvesting performance for d _(15) mode PEH. The experimental U _(p-p), output power and the transient voltagetime curve of PEHSC are in agreement with the results of finite element numerical solutions and theoretical modeling, so they are acceptable. The d _(15) mode and SC structure could potentially improve the energy harvesting performance of PEHs.