Power output estimation and experimental validation for piezoelectric energy harvesting systems

Abstract

Many modern devices especially for ubiquitous computing or wireless sensor networks need a long life energy source. Batteries or accumulators are often an insufficient solution. Low frequency vibrations can be found in the most technical facilities or even in the human movements. Even while these vibrations are neither wanted nor used in the most times, they enable us to generate electrical energy. Piezoelectric flexural transducers are a promising choice for utilizing the vibrations for energy harvesting. There are two major influences on the amount of generated energy. First there is the frequency behavior of the piezoelectric transducers, for optimal power output the transducer should be driven in resonance. Second, the energy output is highly dependent on the electrical load of the connected application. Both circumstances, working frequency and electrical load, typically are boundary conditions for the development of the generator. Therefore, it is necessary to handpick the type of piezoelectric elements. To meet the requirements of development engineers, a model based design method for energy harvesting systems is needed. As a first step towards such a method, this work proposes a model for the estimations of the power output of piezoelectric flexural transducers. For the validation of this model an experiment is described in detail. The results of the model and the experiments are compared.

Analytical determination of characteristic frequencies and equivalent circuit parameters of a piezoelectric bimorph

“…These models using electromechanical analogy have been developed in the past decades on the basis of works by Cady (1922), Van Dyke (1925), and Mason (1935). They have been used, for example, by Roundy et al (2004), Richter et al (2006), and Twiefel et al (2007) to model bimorph structures.…”

A review of piezoelectric energy harvesting based on vibration

“…Twiefel et al 57 investigated the piezoelectric flexural transducers for harvesting power experimentally. They employed working frequency and electrical load as boundary conditions for the development of the generator in analytical model.…”

Nonlinear piezoelectric vibration energy harvesting from a portal frame with two-to-one internal resonance

“…Piezoceramics can be used as a lot of devices, for example, as piezomagnetoelastic structure and harvest energy from an ambient vibration [1][2][3][4][5][6]. A vast and important study of piezoelectric energy harvesting can be found at [7][8][9][10][11][12][13]. These authors explored the re-use of wasted vibration energy in the environment, which is a very important subject, nowadays, to some applications, including renewable energy.…”