Design And Research Of Low-Frequency Vibration Arch Piezoelectric Energy Harvester

The natural environment contains a large amount of energy,which can be divided into renewable(solar,wind,ocean wave energy,etc.)and non-renewable(oil,natural gas,coal,etc.),of which wind and wave energy are clean energy,mostly in the form of horizontal vibrations,and can be collected by energy harvesting devices to convert the vibration energy into electrical energy and store the electrical energy to solve the problem of wireless sensor node self-energy supply.Energy harvesting technology has become a research hotspot in recent years.In this paper,a new type of low frequency vibration arch piezoelectric energy harvester is designed for collecting the vibration energy of nature,the specific research content is as follows:(1)A new low-frequency arch energy harvester was designed.The energy harvester mainly consists of excitation device,gear transmission set,arch type foundation layer and piezoelectric layer.When the upper excitation device is subjected to horizontal vibration,the mechanical energy of vibration will be transferred to the arch foundation layer through the gear transmission set.When the arch foundation layer is deformed,the piezoelectric sheet attached to the foundation layer will also be deformed to convert the mechanical energy into electrical energy.The low frequency horizontal vibration can be "amplified" by the gearing assembly,thus improving the efficiency of energy harvesting.(2)An experimental system of low-frequency arch energy harvester was established.The self-oscillation frequency of the base layer is obtained by displacement measurement and fast Fourier transform,and the effects of the base layer width,piezoelectric sheet size,piezoelectric sheet displacement,base layer vector-to-span ratio,external excitation frequency,load resistance and series-parallel circuit on the piezoelectric response of the energy harvester are analyzed based on the control variable method.The experimental study shows that the electrical output of the energy harvester can be improved by reducing the base layer width,increasing the piezoelectric sheet placement size,placing the piezoelectric sheet in the vault,and reducing the base layer vector-to-span ratio.In addition,the amplification of the horizontal vibration excitation frequency by the gear transmission set of the energy harvester is demonstrated by the arch top displacement measurement.(3)Finite element analysis of the low frequency arch energy harvester was completed.The modal analysis and output voltage time range analysis of the energy harvester were carried out by numerical model,and then the parametric analysis studies of the base layer width,piezoelectric sheet size,piezoelectric sheet position,vector-to-span ratio,arch excitation frequency,load resistance,and series-parallel circuit were carried out.The finite element analysis further verified the general laws of geometric characteristics,load resistance,and series-parallel circuit affecting the piezoelectric response of the energy harvester.Similarly,the analysis of excitation frequency parameters shows that the piezoelectric output of the energy harvester can be improved by using resonant response.