Nonlinear finite element system simulation of piezoelectric vibration-based energy harvesters

Abstract

Piezoelectric vibration-based energy harvesters consist of an electromechanical structure and an electric circuitry, influencing each other. We propose a novel approach that allows a finite element based system simulation of nonlinear electromechanical structures coupled to nonlinear electric circuitries. In the finite element simulation the influence of the electric circuit on the electromechanical structure is considered via the vector of external forces, using an implicit time integration scheme. To demonstrate the applicability of the new simulation method an active power circuit is considered. Several examples of piezoelectric vibration-based energy harvesters, connected to standard or synchronized switch harvesting on inductor (SSHI) circuits, showing linear or nonlinear mechanical behavior, are studied to validate the proposed simulation method against numerical results reported in the literature. The advocated method allows for consistent and efficient simulations of complete nonlinear energy harvesters using only one software tool.

Finite Element Simulation and Comparison of Piezoelectric Vibration-Based Energy Harvesters with Advanced Electric Circuits

“…The FEM based system simulation method introduced in [4] is here applied to simulate a PVEH with three different circuits, a standard, an SSHI and an SECE circuit, and to compare their efficiency. Nonlinear elasticity of the electromechanical structure is taken into account and different magnitudes of a harmonic base acceleration are considered.…”

“…The system simulation method introduced in [4] is applied to simulate a PVEH with a standard, an SSHI and an SECE circuit. Applying the FEM to model an electrode on a surface means to prescribe that all voltage degrees of freedom have the same value ϕ el on this surface.…”

“…The harvested energy and the electric voltage are compared for the standard, the SSHI and the SECE circuit. Some of these results for the standard and SSHI circuits have already been discussed in [4], but here, for the first time, the results for all three circuits are carefully analyzed and compared for different excitation amplitudes.…”

“…Firstly, a magnitude of 0.5 m/s 2 of the harmonic base acceleration is applied. Figure 5 presents the results for ϕ el and the harvested energy of the standard , the SSHI and the SECE circuit from [4]. The considered time period is 0 to 200 ms.…”

“…Simulations of PVEHs based on the Finite-Element Method (FEM) have been introduced and allow for arbitrarily shaped geometries and for modeling nonlinear material behavior. Recently, the authors presented a simulation method using only the FEM and allowing for nonlinear electromechanical structures and nonlinear electric circuits [4]. The influence of the electric circuit on the electromechanical structure is considered via the vector of external forces and an implicit time integration scheme is used.…”