Modeling And Performance Analysis Of Tri-stable Hybrid Piezoelectric Energy Harvester

In recent years,some scholars have begun to study how to use piezoelectric effect to capture energy in the environment and provide energy for low-power microelectronic devices.After years of research and development,piezoelectric energy harvester have many different modes and forms.People have carried out mathematical models and experimental verification on piezoelectric energy harvester with different geometric configurations,and cantilever piezoelectric energy harvester are more common.The main research contents and innovations of this paper are as follows:1.Based on the Euler-Bernoulli beam hypothesis,taking into account the gravitational potential energy of the cantilever piezoelectric energy harvester and the eccentric moment of the magnet at the free end of the beam,the electromechanical coupling equation of the nonlinear bistable piezoelectric energy harvester is constructed by using the Hamilton variational principle,and the analytical expressions of the system displacement,output power and output voltage are obtained by using the multi-scale method.The influence of different system parameters,such as magnet spacing and magnet mass at the free end of the beam,on the energy collection efficiency of the tristable piezoelectric energy harvester under simple harmonic excitation is studied.The calculation results show that the optimal load resistance of the system changes significantly after the gravity potential energy of the piezoelectric energy harvester and the eccentricity of the beam end magnet are introduced into the traditional calculation model.The peak power and effective operating bandwidth of the modified model are larger than those of the traditional model.Therefore,the establishment of a modified model is of great significance to improve the accuracy of the energy capture efficiency of the prediction system.2.A nonlinear bistable piezoelectric energy harvester with a base elastic amplifier is proposed.According to the generalized Hamilton variational principle,the electromechanical coupling equation of the cantilever beam type bistable piezoelectric energy harvester with a base amplifier is derived.The analytical expressions of the system displacement,output power and output voltage are obtained using the harmonic balance method.The effects of the spring stiffness coefficient of different elastic amplifiers,the mass of the magnet at the free end of the beam,the distance between the magnets and the load resistance on the performance of the tristable piezoelectric energy harvester system with a base elastic amplifier under simple harmonic excitation are studied.The results show that the energy collection efficiency of the system with base elastic amplifier is significantly improved compared with the traditional tristable piezoelectric energy harvester with rigid base;The effective working frequency band width of the system increases with the increase of the mass and eccentric moment of the magnet at the free end of the beam.3.An elastic amplifier is added at the fixed end of the beam of the traditional bistable piezoelectric energy harvester,and a nonlinear bistable piezoelectric energy harvester with an elastic amplifier at the beam end is proposed.Based on the generalized Hamilton variational principle,the electromechanical coupling equation of the cantilever beam type bistable piezoelectric energy harvester with a beam end amplifier is established,and the analytical expressions of the system displacement,output power and output voltage are derived using the multi-scale method.The influence of the system parameters such as the spring stiffness coefficient of the elastic amplifier,the mass of the magnet at the free end of the beam and the elastic coefficient of the elastic amplifier on the performance of the tristable piezoelectric energy harvester system with a base elastic amplifier under simple harmonic excitation is studied.The results show that when the mass of the spring at the fixed end of the connecting beam remains unchanged,the energy collection efficiency of the system can be significantly improved by adjusting the ratio of the mass to the mass of the magnet at the free end of the cantilever beam and the stiffness coefficient of the elastic amplifier at the beam end.Figure [96] table [21] reference [54]...