Finite element based system simulation for piezoelectric vibration energy harvesting devices

Abstract

We present a system simulation approach for piezoelectric vibration energy harvesting devices. Accurate modeling of the electromechanical structure is achieved by the finite element method. For consideration of power electronic circuits as a means of energy extraction, the finite element model is iteratively coupled to electric circuits via Simulink. The high computational cost of conventional finite element calculations is overcome by a specialized modal truncation method for general linear piezoelectric structures. In doing so, the simulation approach allows efficient prediction of mechanical quantities (e.g. displacements, stresses) as well as electric potentials in the continuum under the influence of arbitrary electrical circuits. Several examples are studied to validate the truncation approach against analytical models and full finite element models. The applicability of the method is demonstrated for a piezoelectric vibration energy harvester in conjunction with a power electronic circuit.