A Low-Frequency, Broadband Electromagnetic Vibration Energy Harvester Using Magnetic Levitation System and Impact Mechanism

In this paper, a piecewise nonlinear electromagnetic vibration energy harvester (EVEH) using magnetic levitation system (MLS) and impact mechanism is proposed to harvest low-frequency (<15Hz), broadband vibration energy. Different from the conventional magnetic levitation-based EVEH, two mechanical springs are fixed on both ends of the levitated magnet to change the nonlinear stiffness generated by MLS. The output performance is investigated at different initial gaps, mechanical spring stiffness, equivalent spring stiffness, and accelerations. Under the excitation acceleration of Ig, the 3dB working bandwidth can reach to 3Hz (9.5H-12.5Hz), and the maximum peak voltage can reach 1.2V.