Energy Harvesting in a Hybrid Piezoelectric-Electromagnetic Harvester with Time Delay

Abstract

The effect of time delay on the energy harvesting (EH) performance is studied in a class of hybrid EH systems. The delayed hybrid energy harvester consists in a nonlinear mono-stable harvester device composed of a forced mechanical component coupled to piezoelectric and electromagnetic energy harvesting mechanisms in which the time delay is introduced in the mechanical component of the harvester. Analytical approximations of the steady-state amplitude as well as the amplitudes of piezoelectric and electromagnetic powers output are obtained using a perturbation method and the effect of delay parameters on the powers output performance is examined. The optimal values of delay parameters and coupling coefficients at which the EH performance is maximum are determined. To appreciate the influence of the delay amplitude on the powers output performance, the results obtained in the presence of time delay are compared to those obtained in the case without delay. It is shown that in the presence of time delay the powers output performance is significantly improved at certain ranges of time delay and delay amplitude.