Research On Wind-induced Vibration Energy Harvesting System For TPMS

Wind energy is a kind of extensive clean energy. Apart from its application in large-scale wind power project, the micro wind-energy harvester has been studied to be applied in microelectronics and wireless sensors. Modern electronic components are becoming more and more miniaturized, while the disadvantages of battery, such as large size, limited life and replacement needed, have limited its application. Collecting wind energy to supply the device is a feasible way to replace the battery.The paper puts forward a wind energy harvester which can supply the power to TPMS during driving. Firstly, the paper analyzes the principles of conversion from wind energy to electricity and proves the feasibility of the scheme. It then analyzes the velocity of wind which acts on the harvester during movement and found it periodically changing over time. Meanwhile, the simulation of flow field has been carried out by Fluent. When designing the whole system, the implementation scheme of TPMS is carried out first and then the wind-energy harvester is designed utilizing the periodic characteristics, which would vibrate periodically under wind force, gathering wind energy. The device consists of two parts, one is the integration of circuit and TPMS, the other is the energy harvesting structure. The structure is a T shape cantilever with piezoelectric films on the root and its horizontal rectangular plane is extended out of cavity to receive the periodic wind force. Two sides of cavity are open with transverse slender cylinder structure, helping induce the vortex-induced vibration. The size of structure is determined through analysis and Fourier transform method is used here to solve the forced vibration problem of nonharmonic periodic external force. Besides, the theory analysis of periodic excitation vibration of the structure is carried out as well as the finite element simulation by ANSYS Workbench, obtaining the wind energy with a simulation experiment. At the same time, the influence of cylinder structure on air flow in the body cavity is studied by the simulation analysis and experimental comparison, proving it would promote vibration.In the case of 20m/s vehicle forward speed, the structure can generate the vibration with the amplitude of 5.4mm, obtaining the energy of about 0.0231 mW.