Harmonic modeling of vibration energy harvesting systems using extended impedance method

Abstract

Vibration energy harvesting (VEH) systems convert the mechanical vibration energy in AC form into storable electrical energy in DC form. The mechanical structure, electromechanical transducer, and power electronics are three necessary parts for realizing the electromechanical energy transduction and rectification. The difficulty was found in modeling the electromechanical joint dynamics, in particular, when complex mechanical dynamics or sophisticated electrical switching transient are involved. Harmonic analysis is proven to be an efficient tool for modeling such a multiple-field-coupled power conversion system. In this paper, we develop a multiple harmonics analysis for the piezoelectric energy harvesting systems based on the extended impedance method (EIM). This method was used in the analysis of nonlinear power electronic circuits, such as resonant inverters and dc-dc converters. The theoretical results at steady state are compared with the simulation results from the commercialized circuit simulation software. The new modeling technique provides an efficient tool for the customized design and holistic optimization of the vibration energy harvesting systems.