Design And Research Of Vibration Energy Harvester And Energy Management Circuit For Automobile Suspensio

Automobile is one of the main environmental pollution sources.With the development of automobile industry and people’s increasing attention to environmental protection,more and more scholars begin to pay attention to the recycling of renewable energy from automobiles.At the same time,with the rapid development of automotive intelligence and on-board microelectronics technology,the traditional battery has no longer met the needs of development due to environmental pollution,low energy density,the need for regular replacement and other shortcomings.Therefore,how to recycle the renewable energy on the automobile and convert it into usable electric energy has become a hot issue.Tens or even hundreds of watts of vibration energy can be recovered from car suspensions,and the vibration energy recovery efficiency is high,the theory is mature.Therefore,according to the principle of electromagnetic induction,a nonlinear electromagnetic vibration energy harvester is designed for automobile suspension,and two energy management circuits are designed according to the output characteristics of vibration energy harvester.In this paper,the vibration energy harvesting of automobile suspension is taken as the background,a vibration energy harvesting system is designed,which consists of vibration energy harvester and energy management circuit.The output characteristics of the vibration energy harvesting system is studied explicitly.The research content of this paper includes four parts:(1)A nonlinear electromagnetic vibration energy harvester was designed for the vehicle suspension,and a mechanical model for the quarter vehicle with the energy harvester was built.In order to make a comparative study,the linear vibration energy harvester and the mechanical model for quarter vehicle with linear vibration energy harvester are introduced simultaneously.The output voltage and output power of two vibration energy harvesters are compared and studied,and the energy recovery efficiency of two vibration energy harvester is compared.(2)The structural optimization of nonlinear vibration energy harvester is actualized,and influence of structural parameters such as spring stiffness,lever amplification factor,coil parameters and magnetic distance on the output characteristics of vibration energy harvester are studied.The optimum structural parameters of vibration energy harvester with maximum output power are obtained.Then,the influence of external parameters such as road class,vehicle speed and load resistance on the output characteristics of vibration energy harvester is studied.Finally,whether the introduction of vibration energy harvester affects the ride comfort of the vehicle is studied.(3)According to the output characteristics and the electromechanical equivalent model of the vibration energy harvester,a self-powered energy management circuit is designed according to the principle of impedance matching.Each module of the energy management circuit is analyzed in detail,and the influence of speed and road class on the output voltage,output power and energy conversion efficiency of the energy management circuit is studied.Finally,the feasibility and effectiveness of electromagnetic vibration energy harvesting system are verified by experiments.(4)for the sake of improving the output power and energy conversion efficiency of the vibration energy harvesting system further,an energy management circuit is designed by using the perturbation observation algorithm of maximum Power Point tracking(MPPT)technology.The value range of sampling time and perturbation duty cycle of two important parameters in perturbation observation algorithm is theoretically analyzed.The proposed perturbation observation algorithm is simulated and tested by Matlab/Simulink,and the effect of different parameter selection on the output power and the energy conversion efficiency of energy management circuit is studied.