Exploring coupled electromechanical nonlinearities for broadband energy harvesting from low-frequency rotational sources

Abstract

This paper presents a methodology to effectively harness low-frequency broadband rotational energy using coupled electromechanical non-linearities. This design integrates bi-stability and a synchronized switch harvesting on inductor (SSHI) circuit into a frequency up-converting harvester. The bistable behaviour enables improved output power due to the increased vibration amplitude under the same input plucking force. The SSHI circuit exhibits enhanced conversion capability, contributing higher electrical damping which is ideal for frequency up-converting harvesters to alleviate output power fluctuation at high frequencies. To study the coupled nonlinear dynamics from both the mechanical (bi-stability) and electrical (SSHI) sides, a system-level theoretical model is, for the first time, established and numerically solved using Matlab/Simulink. System behaviours, which would not be able to obtain using circuit simulation methods, are studied for different operating frequencies and load resistances. To validate the theoretical analysis, this harvester was implemented and tested experimentally. A close match was obtained. From the experimental results, an enhanced output power (up to 525%), over a broad frequency range, was realized, compared to that of a harvester with neither bi-stability nor SSHI circuits.

Hybrid energy harvesting technology: From materials, structural design, system integration to applications

“…The overall system-level efficiency will generally be substantially lower. The component-or system-level conversion efficiency and fundamental methods have been discussed in [190,191]. In summary, conversion efficiency enhancement, electronic component count reduction and power loss reduction can all be realized in a power management circuit by designing the system in a holistic manner.…”

A Magnetic-Coupled Nonlinear Electromagnetic Generator with Both Wideband and High-Power Performance

“…To increase the output power and broaden the operating bandwidth of the vibration generators, various approaches, such as oscillator arrays [ 27 ], multi-modal oscillators [ 28 , 29 ], and active or passive frequency tuning technologies [ 30 ] have been proposed. In addition, researchers have exploited numerous approaches to introduce nonlinearity into vibration generators, including monostable Duffing oscillators [ 31 , 32 ], bistable oscillators [ 33 , 34 , 35 ], and frequency-up-conversion technologies [ 36 , 37 ] etc. The above mechanisms are commonly used in PEGs, EMGs, and TENGs.…”

A combined nonlinearity mechanism for potential well shaping of MEMS bi-stable energy harvester

“…However, regardless of the adopted conversion mechanism [7], most VEHs are designed based on linear oscillator with narrow working bandwidth [8]. Therefore, extensive mechanisms are proposed for broadband energy harvesting [9,10], and bi-stable nonlinearity attracts much attention due to the advantages of the large-amplitude snap-through behavior in enhancing energy output over wider frequency range [11][12][13][14].…”