Structural Modification Towards Higher Magnetic Flux Density in Radial Rotational Energy Harvester

Electromagnetic rotational energy harvesters are frequently used for harvesting the kinetic energy of vehicles and pedestrians. In the research of related fields, better magnetic flux density performance inside the harvester has always been a goal pursued by researchers and manufacturers. This work presents the effect of different magnet and coil layout schemes on the magnetic flux density in a radial electromagnetic rotational energy harvester during operation under equal volume conditions. The simulation results obtained using Finite Element Magnetic Methods (FEMM) tool indicate that the layout of Halbach array with specific pole number is better than the array with maximum pole number, while a thicker cylindrical air-core coil is more favorable for the magnetic flux density value in the power generation process under equal volume conditions. In addition, hat-shaped coil with a specific inclination angle is also superior to traditional cylindrical coils. A maximum increase of 2.6 times in magnetic flux density can be achieved, with a peak output power increase of up to 4.13 times.