Dynamics and energy generation of a hybrid energy harvester under colored noise excitations

Abstract

A hybrid energy harvester combining piezoelectric and electromagnetic transduction mechanisms is presented, which can be extensively applied in harvest vibration energy. This paper studies power harvested from the hybrid harvester under additive and multiplicative Gaussian colored noise excitations. Based on the stochastic averaging method, approximate methods have been adopted to obtain the Fokker-Planck-Kolmogorov equation and reveal interesting dynamics related to the stationary probability density, mean harvested power and mean switching time. It is observed that noise intensities, correlation times and other system parameters will induce the appearance of stochastic bifurcation. Furthermore, the mean harvested power is carried out to understand the device output performance of the hybrid generators. The hybrid energy harvested can be enhanced by suitable choice of noise intensities, correlation times and other system parameters. Finally, the mean switching times of the periodic attractors are investigated. The phenomenon of noise-enhanced stability has been carried out to evaluate the performance of the hybrid energy harvester. The occurrence of the noise-induced stability phenomenon signifies that the stability of the large-amplitude periodic attractor can be enhanced by the noises, which is very beneficial for energy harvesting.