Analysis And Optimization Design Of Cantilever Magnetostrictive Vibration Energy Harvester

In the past few years,with the purpose of retarding the excessive depletion of fossil energy,scholars at home and abroad have devoted themselves to finding new energy sources and developing new green energy technologies.Vibratory power generation technology is proposed as a sustainable green trend direction to solve the environmental problems that exist when batteries need to be disposed of after use.The rapidly growing solid-state electronics market is leading the development of ultra-low-power equipment and self-powered devices,and the power required for commercial unicircuit and ultra-low-power equipment has been reduced toμW.In order to replace batteries as the main power source for low-power electronic equipment,vibration energy harvesters can be used to gather vibration energy from the natural world to power ultra-low-power appliances.Based on the working principle and the difference of functional materials,magnetostrictive vibration energy harvesters have high transfer efficiency,high output power,and high energy density.In this paper,Fe-Ga alloy is used as the core component,and its magnetostrictive inverse effect is applied,combined with Faraday electromagnetic effect as the main working principle.In order to develop a new type of Fe-Ga alloy magnetostrictive vibration energy collector which is suitable for forced excitation and free excitation,and obtain vibration energy from it,a cantilever vibration energy collector based on Fe-Ga alloy is designed,and the structural configuration,bias mode,substrate material and size,external impedance and other factors affecting the working capacity of the collector are systematacially analyzed,and the methods to improve its working capacity and mediate the working frequency range are clarified.The method of improving its working capacity and mediating the working frequency range is clarified,which provides ideas for further system optimization design.First,the machine-magnetism-electricity coupling mathematical model of the cantilevered Fe-Ga alloy as vibration energy harvester is established,and the mechanism of mechanical to electrical energy conversion of magnetostrictive materials is clarified.Then,the energy harvesting performance of the energy harvester prototype is further analyzed,including its resonance characteristics,open-circuit output voltage frequency response and amplitude characteristics under base excitation,the effect of external resistance,and the energy harvesting performance under free excitation.Meanwhile,the influencing factors of the cantilevered Fe-Ga as vibration energy collector output electric energy are studied by combining theory and experiment,including the elaboration of physical parameters,geometric structure and bias magnetization conditions.And the methods to further improve the vibration energy harvesting capacity through in-depth experiments.The influence of the number of layers,arrangement and structural parameters of the composites on the performance of vibration collection and conversion were studied.It is clearly demonstrated that the magnetic fields of the biomagnetic and electromagnetic shakers have almost no effect on the measured induced voltage of the energy collector.The output power rms value reaches 13.3 m W and the power density rms value reaches 3.7 m W/cm~3/g.In volume power density respect,the volume power density of the vibration energy harvesting prototype without pre-magnetization field is 2.653 m W/cm~3 when connected in series with the best matched resistive load.the average conversion efficiency is about 17.7%when connected in series with 200(?)resistor without pre-magnetization field.The designed cantilevered Fe-Ga alloy as vibration energy harvester successfully powers multiple sinusoidally connected red light-emitting diode lamps and multiple red digital tubes,checking the vibration energy collecting capability and generating capacity of the energy harvester.