Study the influence of magnetic force on nonlinear energy harvesting performance

The effect of magnetic force on nonlinear energy harvesting performance is discussed theoretically and experimentally in this paper. A kind of nonlinear magnetic coupled piezoelectric energy harvester (NMPEH) is designed. The bidirectional screw is used to adjust the relative location of the tip magnets and external magnets to get different nonlinear magnetic forces. It is well known that the nonlinear magnetic force will influence the broadband energy harvesting performance. In order to describe the nonlinear dynamic behavior of the NMPEH, harmonic balance method is employed and its excitation test are performed at different accelerations over the range of 5-30Hz. It is also found that the analytical solutions match well with experimental output voltage. The nonlinear energy collector under the influence of symmetric magnetic force studied in this paper can not only reduce the resonance frequency of the system, but also increase the vibration amplitude of the cantilever beam, thus increasing the power obtained from the vibration environment.