by Jens Twiefel, Björn Richter, Tobias Hemsel, Jörg Wallaschek
Abstract:
In the design process of energy harvesting systems based on piezoelectric elements, achievable energy output is the most interesting factor. To estimate this amount a priori manufacturing of prototypes a mathematical model is very helpful. Within this contribution we will introduce a model based on electro-mechanical circuit theory. Its parameters are identified by measurements and the model is validated by comparison to experimental results. The model is designed to support the development-engineer in the dimensioning of energy harvesting units to specific application demands. Two main challenges in device design are investigated with the mathematical model: influence of the ambient excitation frequency, and influence of the load impedance. Typically, the equivalent model approach delivers models for piezoelectric elements that are driven in resonance by electrical excitation. In the case of energy harvesting the piezoelectric elements are excited mechanically and most often non-resonant. Thus, we first set up a mechanical equivalent model for base excited systems. In first approximation it represents an energy harvesting unit around one resonance frequency. The model is expandable for a wider frequency range using the superpositioning of multiple circuits. From the viewpoint of optimum energy transformation between mechanical and electrical energy it is favorable to drive piezoelectric elements at resonance or anti-resonance. Thus, an energy harvesting system should be tuned to the excitation frequency.
Reference:
Twiefel, J.; Richter, B.; Hemsel, T.; Wallaschek, J.: Model-based design of piezoelectric energy harvesting systems. volume 6169, 2006.
Bibtex Entry:
@PROCEEDINGS{Twiefel2006a,
title = {Model-based design of piezoelectric energy harvesting systems},
year = {2006},
volume = {6169},
__markedentry = {[K. Agbons jr:6]},
abstract = {In the design process of energy harvesting systems based on piezoelectric
elements, achievable energy output is the most interesting factor.
To estimate this amount a priori manufacturing of prototypes a mathematical
model is very helpful. Within this contribution we will introduce
a model based on electro-mechanical circuit theory. Its parameters
are identified by measurements and the model is validated by comparison
to experimental results. The model is designed to support the development-engineer
in the dimensioning of energy harvesting units to specific application
demands. Two main challenges in device design are investigated with
the mathematical model: influence of the ambient excitation frequency,
and influence of the load impedance. Typically, the equivalent model
approach delivers models for piezoelectric elements that are driven
in resonance by electrical excitation. In the case of energy harvesting
the piezoelectric elements are excited mechanically and most often
non-resonant. Thus, we first set up a mechanical equivalent model
for base excited systems. In first approximation it represents an
energy harvesting unit around one resonance frequency. The model
is expandable for a wider frequency range using the superpositioning
of multiple circuits. From the viewpoint of optimum energy transformation
between mechanical and electrical energy it is favorable to drive
piezoelectric elements at resonance or anti-resonance. Thus, an energy
harvesting system should be tuned to the excitation frequency.},
author = {Twiefel, Jens and Richter, Bj{\"o}rn and Hemsel, Tobias and Wallaschek,
J{\"o}rg},
bdsk-url-1 = {http://dx.doi.org/10.1117/12.658623},
doi = {10.1117/12.658623},
journal = {Proc. SPIE},
owner = {K. Agbons jr},
pages = {616909-616909-10},
timestamp = {2013.11.23},
url = {http://dx.doi.org/10.1117/12.658623}
}