Research On Optimal Design Of Energy-harvesting Structures And Energy-harvesting Circuits For Wind-induced Motion Energy

Micro sensors,MEMS and many other low-energy electronic products has been widely used these years.Due to the many drawbacks of the traditional battery power supply methods,the research on how to continuously and stably supply energy for microelectronic products is the main problem faced by researchers.In recent years,as a novel,efficient and environmentally friendly energy source,the piezoelectric flowinduced motion energy harvester has gradually become a research hotspot.This paper optimizes the design of the bluff body,cantilever beam and energy harvesting circuit of the wind-induced motion energy harvester to improve the energy harvesting efficiency.Firstly,the physical model of the wind-induced motion piezoelectric energy harvester is established.The single-degree-of-freedom system is introduced to analyze the system control equation and fluid dynamics equation,and the power transfer characteristics of four typical energy harvesting circuits are introduced.Using simulation software to simulate bluff bodies and cantilever beams with different shapes,the results show that the D-shaped bluff body is the best shape choice;the cantilever beams are sorted according to the ideal degree of the strain curve:triangle,concave trapezoid,trapezoid,convex trapezoid,rectangle.An experimental platform has been built to test different shapes of bluff bodies and cantilever beams.The results show that the D-shaped column with a flat windward surface and a scale ratio of 1.732 and 2 has the best energy harvest characteristics;The optimal size of the rectangular cantilever beam is determined,and the optimal shape of the non-rectangular cantilever beam is determined as a concave trapezoid.A spliced cantilever beam with two materials has been designed and tested,which combines lower working wind speed and higher output voltage.Four kinds of energy harvesting circuits were simulated using Multism software.The peripheral circuit is built based on the LTC3588 chip,thus broadening the input voltage range and enriching the circuit functions.The circuit can stably output the specified voltage when the energy harvester works.