Energy harvesting from quasi-periodic vibrations

Quasi-periodic (QP) vibration-based energy harvesting is studied in this paper. The energy harvesting system consists in a delayed van der Pol oscillator with time-varying delay amplitude coupled to an electromagnetic energy harvesting device in which the vibration source is due to self-excitations. We consider the case of delay parametric resonance for which the frequency of the delay modulation is near twice the natural frequency of the oscillator. Application of the double-step perturbation method enables the approximation of the amplitude of the QP vibrations of the oscillator far from the resonance. This amplitude is used to extract the maximum and average QP powers from the harvester device. The influence of different system parameters on the performance of the QP vibration-based energy harvesting is reported and discussed. Results show that for appropriate values of parameters, QP vibrations can be more efficient for energy harvesting in pure self-excited systems not only in terms of power extraction, but also in terms of broadening the parameter range of energy extraction. Numerical simulation is systematically conducted to support the analytical predictions.