Affiliations: [a] Department of Mechanics, Huazhong University of
Science and Technology, Wuhan 430074, China | [b] Department of Mechanical Engineering, University of
California, Riverside, CA 92521, USA
Abstract: The interaction between a harvesting structure and a storage circuit
is modeled using a full-bridge rectifier. In order to focus on the challenges
associated with modeling the intrinsic nonlinearity of the rectifier, the
authors have considered a piezoelectric plate in the thickness-stretch mode of
oscillation and have represented the storage circuit by a simple LRC circuit in
this first attempt. It is found that the primary performance of such a model
energy harvester can be characterized by two non-dimensional parameters, i.e.,
the non-dimensional aspect ratio of the piezoelectric plate and the
non-dimensional inductance of the LRC circuit, and that the power density of
this model harvester can be optimized by adjusting these two parameters
properly. Specifically, for each fixed non-dimensional aspect ratio there
exists an optimal non-dimensional inductance, at which the power density is
maximized, and conversely, for each fixed non-dimensional inductance there is
an optimal non-dimensional aspect ratio, leading to a maximum of the power
density when the volume of the plate is kept constant. The analysis for this
simplified model piezoelectric harvester, though not realistic, provides a
framework for further development on design guidelines for piezoelectric energy
harvesters of optimal performance.
