Desenvolvimento teórico e experimental de um gerador de energia elétrica utilizando a energia vibratória de sistemas mecânicos com base nos materiais piezoelétricos

Abstract

Energy harvesting from environmental sources is a promising technique with great potential that can contribute to the generation of clean electric energy from renewable sources, suitable for the operation of self-powered, low-power electronic devices. In this sense, this work aims to develop and evaluate the performance of a device that transforms mechanical vibrations present in the environment into electric energy using Lead Zirconium Titanate (PZT) piezoelectric ceramics. The generator was constructed as a mechanical structure capable of providing cyclic deformations to eight piezoelectric cells, through tensile/compressive loads. Prior to the construction of the device, its geometric dimensions were established through a finite element analysis. For the acquisition of the experimental results a duly instrumented measurement system was used, where it was possible to obtain data regarding the acceleration, voltage and electric power generated by the device. The results from numerical and experimental analyses - related to the dynamics of the device and the generated electric voltage, are presented and compared. The generator was evaluated for different vibration amplitudes and generated a maximum power of 9.6 mW when operating at its first natural frequency (60 Hz), considering a resistive load of 15 kΩ. Finally, the performance of the generator was evaluated under two different ambient excitation conditions, when coupled to an air condition condenser and when coupled to a three phase induction motor.