Design and Numerical Simulations of Low-Frequency Vibration Energy Harvesting Device

A new vibration energy harvesting device which is adept at working under the condition of low-frequency vibration is designed in this paper.This device is constructed including several closed magnetic circuits which significantly improve the ability of energy harvesting.Meanwhile,the rack structures in the device lead to the change frequency of the coil magnetic field increasing,so that the device can adapt to work with low frequency vibration.After illustrated the structure and principle of the device,a series of numerical simulations using Ansoft Maxwell is introduced.While the static simulations expose the relationship between the relative permeability of ferromagnetic material and the maximum coil magnetic flux density as well as the relationship between the width of air gap and the maximum coil magnetic flux density;the dynamic simulations show the induced voltage and energy dissipation of the device.Based on the data of the simulations,the maximum average power when the frequency of vibration is 1 Hz is calculated,and it is much better than that of the similar device reported in other papers.It demonstrates that the new low-frequency vibration energy harvesting device is able to power for wireless sensor network nodes.