Magnetic flux density analysis of magnetic spring in energy harvester by Hall-Effect sensors and 2D magnetostatic FE model

The paper investigates the magnetic properties and design of energy harvester system including the magnetic spring and vibration generator. The magnetic flux density measurements were conducted by means of Hall-Effect magnetic sensors mounted on the magnetic spring. The amplitude of variable component of the magnetic flux density in the magnetic spring depends on the vibrations frequency resembled by vibration generator. In the magnetic spring, two resonant frequencies at 86 Hz and 110 Hz are identified and the reached maximum amplitude value of magnetic flux density is ∼1mT. To confirm the usefulness of the manufactured magnetic spring, the calculation of the magnetic flux density in 2D axis-symmetric model of vibration generator and magnetic spring has been carried out using the Ansys Maxwell. The results of the simulation are in accordance with the measurements. Through simulation analysis and laboratory measurement tests, a better understanding of the properties of magnetic springs prototype has been achieved.