The Performance Analysis Of Cantilever Beam Piezoelectric Energy And The Design Of A New Type Of Energy Harvester

The energy issue is one of the hot issues in the world today.Researchers in various countries are all seeking and developing new energy sources to solve the problems of energy shortage and the use of traditional energy sources.Vibration energy is a common energy source in automobile.Vibration energy harvester is a device that transforms mechanical energy of vibration into electric energy.The frequency of vehicle vibration noise ranges from 5Hz to 300 Hz,which belongs to the low-frequency category.However,the technology of efficient energy harvest under low-frequency environment is the focus and difficult problem in the field of energy collection research.For the collection of low-frequency energy,the current research work is only effective in a narrow frequency band(<2Hz),but the exciting sources in the real environment are often changed in a wider frequency band.However,the existing design methods are all based on the optimization of circuit parameters in a certain structural form,or the design of piezoelectric structures without considering the influence of circuit parameters,and the collaborative design of the piezoelectric structure configuration and circuit parameters is not discussed.Therefore,in order to improve the energy recovery efficiency under low-frequency environment,we must solve the problem of too narrow frequency band.The structure of the piezoelectric structure and the energy storage circuit parameters in the energy-capture system have an important influence on the energy-capturing efficiency,and the piezoelectric structure and the circuit parameters interact and couple with each other.The structure of the piezoelectric and the parameters of the energy storage circuit both have an important influence on the energy-capturing efficiency,and the piezoelectric structure and the circuit parameters interact with each other.For this reason,the analytical model of the equivalent parameters of the piezoelectric structure is given in theory at first.Then the accuracy of the model is verified by experiments.On this basis,we have established a cooperative optimization method for energy harvester and energy harvest circuits.Finally,a new type of energy harvester based on mechanical induction is proposed and verified by experiments.The main research work of the paper is as follows:(1)Aiming at a rectangular piezoelectric cantilever beam with unequal piezoelectric,the equivalent parameter model of the piezoelectric energy harvester is given,and the accuracy of the equivalent parameter model is verified by experiments.(2)Based on the established equivalent parameter model,the effects of the piezoelectric energy harvester and the energy harvest circuit on energy harvesting performance are studied.And a cooperative optimization design of piezoelectric energy harvester considering the influence of energy harvest circuit and impedance is also carried out.The research results show that when the load is given,the power of harvester will increase first and then decrease with the length ratio of piezoelectric to cantilever.Under optimal load,the power of harvester increases with the increase of thickness ratio of piezoelectric to cantilever beam.The electromechanical coupling coefficient increases first and then decreases with the length ratio and thickness ratio of the piezoelectric sheet and the cantilever beam.The optimal length ratio and thickness ratio make the electromechanical coupling coefficient reach the maximum value.The load adaptability of the harvester with different length ratio is analyzed.The cooperative design between the energy harvester,the energy harvest circuit and load adaptability is realized to maximize the output power of the energy harvester.(3)A new type of energy harvester based on mechanical induction was proposed.The simulation results show that the new type of energy harvester can effectively increase the vibration amplitude under a tiny excitation signal and increase the vibration bandwidth under the action of the mechanical inducer.The open-circuit output voltage is up to 2.3 times that of the traditional piezoelectric cantilever beam and the energy harvester's bandwidth is 1.7 times that of traditional piezoelectric cantilever beam.(4)Build a vibration test platform.The experimental results are in good agreement with the simulation results,which verify the feasibility of the new type of energy harvester based on mechanical induction...