Research On The Design And Output Performance Of Electromagnetic Vibration Energy Harvester

Vortex-induced vibration caused by wind energy is a research direction that many researchers are keen on in recent years.Based on the existing research on electromagnetic vibration energy harvester,this paper designs an electromagnetic vibration energy harvester that uses the principle of vortex-induced vibration to obtain wind energy,including vibration picking structure and energy conversion system.Among them,the vibration picking structure converts wind energy into mechanical kinetic energy,an energy conversion system converts mechanical kinetic energy into electrical energy.The main contents of this paper are as follows.1.The functional model and three-dimensional geometric model of electromagnetic vibration energy harvester were established.The basic physics modeling of the energy harvester is carried out,its motion equation is established,the expression formula of the response amplitude and phase of the collector is derived,and the influence of frequency ratio and damping ratio is analyzed according to the amplitude expression formula.When the frequency ratio is analyzed to be 1,the collector can obtain the maximum amplitude and maximum power.2.The dynamic analysis of the vibration pickup structure of electromagnetic vibration energy harvester was carried out.First,different sizes are set for the cantilever beam to obtain the influence of different dimensions on the natural frequency of the cantilever beam.The design cantilever beam size is 260×20×1mm,and the cylindrical wind collection blunt body size is 180×70mm.The ANSYS modal analysis of the entire pickup structure was carried out,and its first-order natural frequency of 4.13Hz was established as the main operating frequency.Then,a harmonic response analysis is performed to verify that the maximum amplitude can be achieved at the main operating frequency of 4.13Hz.3.Three magnet arrangement schemes were designed for the transducer system:(1)a magnetic ring in the same polar direction;(2)Halbach magnet array without spacing;(3)Equal-pitched Halbach magnet array.The Ansoft Maxwell 2D module was used to analyze the magnetic field lines,magnetic induction intensity and magnetic field strength of the three schemes,and verified that the unilateral enhancement of the Halbach magnet array could effectively enhance the magnetic field.The motion trajectory of the coil is solved,and then,the Ansoft Maxwell 3D module is used to perform transient simulation of the three schemes,and the simulation results show that the rms value of the output voltage of the copolar magnetic ring is about 0.75V,the rms value of the output voltage of the unpitched Halbach permanent magnet array is about 1.17V,and the rms value of the output voltage of the equidistant Halbach permanent magnet array is about 1.02V.The results show that the pitchless Halbach permanent magnet array can effectively increase the voltage output performance of the transducer system.4.Build an experimental platform for verification.When the wind speed is 2m/s,the vibration pick-up structure can obtain the maximum amplitude,and the amplitude response curve is subjected to fast Fourier transform to obtain the spectrum diagram.At this time,the operating frequency is about 4.35Hz,which is basically close to 4.13Hz of the wind bluff body.The voltage output performance of the three magnet schemes is tested.The effective value of the output voltage of the homopolar magnetic ring is about 0.53V,the effective value of the output voltage of the non-spacing Halbach permanent magnet array is about 0.94V,and the effective value of the output voltage of the equidistant Halbach permanent magnet array is about 0.79V,which proves that the magnetic field enhancement effect of Halbach can effectively increase the voltage output performance.Furthermore,the amplitude of the double cylindrical bluff body is tested.The maximum amplitude is increased from 10-12cm to 10-20cm,and the effective working wind speed can be in the range of 2.5-4.5m/s,which broadens the working frequency and enables it to achieve effective voltage output in more environments.