Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
Design and Optimization of an Electromagnetic Energy Harvester for Wireless Sensors Applications
Submission Author:
Airton José Schmitt Junior , SC , Brazil
Co-Authors:
Airton José Schmitt Junior, Julio Cordioli, Danilo Braga
Presenter: Airton José Schmitt Junior
doi://10.26678/ABCM.COBEM2023.COB2023-2232
Abstract
In the last few decades, Vibration Energy Harvesting (VEH) techniques have become promising alternatives for supplying low-power equipment, such as wireless sensors and vibration monitoring devices. Nowadays, most VEH technologies can be easily integrated into Internet of Things (IoT) systems and are capable of providing real-time monitoring of assets and health indicators of a machine. Moreover, the autonomy of wireless sensors has been significantly increased with VEHs, in contrast to the usage of conventional batteries, which can provide no more than 10 years of autonomy in general. The vast majority of existing VEHs can be classified into four main categories, according to the transduction principle behind their operation: Piezoelectric; electromagnetic; electrostatic and magnetostrictive harvesters. This work presents the design and optimization of a commercial vibration transducer. Such a device contains in its interior a resonant-type electromagnetic generator that can be modeled as a 1 DoF (Degree of Freedom) system, the latter composed by a seismic mass and a mechanical spring, as well as other components. The complete set weighs about 90 g and occupies a total volume of approximately 50.97 cm³, being able to generate up to 45 mW at its resonance frequency of 60 Hz, with a bandwidth of 2.5 Hz. Furthermore, the linear generator presented in this article reaches a maximum Normalized Power Density (NPD) of 1.8018 mW/cm³/g² at an acceleration amplitude of 0.7 g (~ 6.67 m/s²). A numerical model was developed via commercial software Comsol Multiphysics, in order to model the electromechanical system and to proceed with further optimization, from which it was possible to optimize its geometry and maximize its NPD and power output. A Surrogate optimization algorithm was then implemented in MATLAB, in which both volume and mechanical stress were considered as project constraints. The optimized geometry is under prototyping and its performance is compared in terms of NPD with the commercial transducer.
Keywords
Vibration Energy Harvesting, Electromagnetic Generator, Numerical Modeling, Optimization, Normalized Power Density
