Dynamic Characteristics of Electromagnetic Energy Harvester using

Abstract

In recent years, energy harvesting from vibration is drawing attention as one of the methods to supply power to sensors. The aim of our study is to obtain design guidelines for energy harvesters with high energy conversion efficiency through vibration testing and analytical modeling. In this study, an energy harvester that generates power by the principle of electromagnetic induction caused by vibrating two permanent magnets that are linearly placed along a cylindrical housing are proposed. The prototype of the energy harvester has been designed and fabricated. By mounting the harvester on an electrodynamic shaker and applying base excitation to the harvester, vibration testing was performed. Parametric studies have been conducted by changing the conditions such as the input displacement, the polarity of the magnets and the frequency of the input base displacement. According to the results of experiment, it is shown that it increases the amount of generated power when the magnets are installed with opposite polarity with each other. In addition, in the case of attractive force, the numerical analysis model of the electromagnetic induction type energy harvester using the twodegree-of-freedom oscillator was constructed and the dynamic analysis was performed. In the numerical analysis, the damping coefficient was identified so that the natural frequency and the resonance peak coincided with each other. Good agreements between the experimental results and the numerical analysis results have been observed near the resonance, and the validity of the constructed model and the damping coefficient identification results were confirmed.