Dynamics and coherence resonance of tri-stable energy harvesting system

• Published in: Smart materials and structures Vol. 25; no. 1; pp. 15001 - 15012
• Main Authors: Haitao, Li, Weiyang, Qin, Chunbo, Lan, Wangzheng, Deng, Zhiyong, Zhou
• Format: Journal Article
• Language: English
• Published: IOP Publishing 01.01.2016
• Subjects: Coherence; coherence resonance; Devices; Dynamical systems; Energy harvesting; energy harvesting system; Excitation; Magnetic resonance; Mathematical models; Power efficiency; tri-stable state
• ISSN: 0964-1726; 1361-665X
• DOI: 10.1088/0964-1726/25/1/015001

To improve the efficiency of energy harvesting, this paper presents a tri-stable energy harvesting device, which can realize inter-well oscillation at low-frequency base excitation and obtain a high harvesting efficiency by tri-stable coherence resonance. First, the model of a magnetic coupling tri-stable piezoelectric energy harvester is established and the corresponding equations are derived. The formula for the magnetic repulsion force between three magnets is given. Then, the dynamic responses of a system subject to harmonic excitation and Gaussian white noise excitation are explored by a numerical method and validated by experiments. Compared with a bi-stable energy harvester, the threshold for inter-well oscillation to occur can be moved forward to the low frequency, and the tri-stable device can create a dense high output voltage and power at the low intensity of stochastic excitation. Results show that for a definite deterministic or stochastic excitation, the system can be optimally designed such that it increases the frequency bandwidth and achieves a high energy harvesting efficiency at coherence resonance.