Transient response of a nonlinear energy sink based piezoelectric vibration energy harvester coupled to a synchronized charge extraction interface

Abstract

Integration of a piezoelectric transducer with a nonlinear energy sink (NES) has been realized for both vibration mitigation and broadband energy harvesting. However, to ensure that a harvester can generate power in a truly broadband manner, the impedance matching issue of the interface circuit should be addressed. The synchronized charge extraction (SCE) is one technology that has been proved to be able to address this issue for linear energy harvesters. This work intends to investigate the transient response of an NES-based piezoelectric vibration energy harvesting system interfaced with an SCE interface (NESVEH-SCE). The nonlinear normal mode of such an electromechanically coupled system is analyzed on the basis of the equivalent impedance method and complexification-averaging method. The frequency-energy plots are depicted and verified by wavelet analysis. The effects of electromechanical coupling strength, electrical load in the SCE interface and initial input energy level on the performance of the proposed system are discussed by using the circuit simulation tool. Finally, experiments are performed to verify the consequences obtained from the theoretical and numerical methods, and demonstrate that the energy harvested during the transient response of the NESVEH-SCE system is independent of the electrical load in the SCE interface.