Nonlinear energy harvesting based on a rotating system

A simple electromagnetic energy harvester with the cubic nonlinear stiffness is proposed, and the characteristics of dynamic responses as well as the potential power harvested are studied in this paper. The proposed nonlinear electromagnetic vibration energy harvester can be installed on the host base that is rotating at a constant speed and vibrating vertically. Considering the combination of the vertical vibrating and rotating frequency of the host base, the 1:1 primary resonance is investigated by the method of multiple scales. The dynamic characteristics of responses in terms of system parameters are studied and the bifurcation curves are constructed. In addition to possessing the resonance characteristics, some saddle-node bifurcations occur for the steady-state solutions under certain conditions. Moreover, the effects of system parameters on the output average power are investigated as well. The results of analysis show that multiple frequency bands and parameter regions are existed where the large power can be harvested due to the resonance condition and nonlinearity of the system. Introducing the nonlinearity not only can increase the
value of the output power but also expand the frequency bands and parameter regions to harvest the large power. A carefully selected system parameters can help to optimize the average power harvesting in the design.