Equivalent Impedance Electroelastic Modeling of Multiple Piezo-Patch Energy Harvesters on a Thin Plate With AC–DC Conversion

摘要

Piezo-patch energy harvesters can be readily attached to plate-like structures in automotive, marine, and aerospace applications, in order to exploit the broadband vibration of the host system. Power output investigations of such patch-based harvesters, when connected to practical interface circuits, require accurate models for harvesting performance evaluation and optimization. This paper proposes an analytical approach to derive the closed-form mechanical and electrical response expressions of the multiple piezo-patch energy harvesters (MPEHs) by integrating an equivalent load impedance, which consists of the harvesting circuit and the overall piezo-patch capacitance into a distributed-parameter model of the plate. Moreover, an equivalent circuit model of the electromechanical system is developed in a circuit simulator software SPICE for system-level simulations, taking into account the interconnection of piezo-patches and multiple vibration modes of the plate. Numerical SPICE simulations are then validated for the conventional ac input–ac output problem by the experiments and existing analytical solution. The proposed analytical model is validated by the experiments for the standard ac input–dc output problem. Finally, the analytical and numerical results for the peak power output of the MPEHs in series/parallel configuration with ac and dc interface circuits are presented, and shown to be in good agreement with the experimental results.