Modeling and analysis of a three-degree-of-freedom piezoelectric vibration energy harvester for broadening bandwidth

This study proposes a multi-frequency response piecewise-linear piezoelectric vibration energy harvester (MFRPLP-VEH) by combining the linear multi-frequency resonance and nonlinear vibration bandwidth broadening methods to improve the working frequency bandwidth and environmental robustness of the piezoelectric vibration energy harvester. A theoretical model is established based on the electromechanical coupling and the dynamic response of the MFRPLP-VEH. The energy harvesting performance and broadening width efficiency of the MFRPLP-VEH were obtained through an experimental verification platform, where the resonant frequencies of the three beam are 28.9, 33.6, and 38.6 Hz, respectively. Furthermore, the operating frequency range is widened by 90.9% at an external excitation acceleration of 10 m/s². The energy generated by the MFRPLP-VEH is 194% of the energy generated by its linear counterpart under the same excitation conditions. The numerical and experimental results verify the accuracy of the theoretical model and the broadband working frequency range of the MFRPLP-VEH.