Dynamic Characteristic Analysis of Tri-Stable Piezoelectric Energy Harvester with Double Elastic Amplifiers

Abstract

In order to further improve the vibration energy harvesting efficiency of piezoelectric energy harvester under low frequency environmental excitation, this paper, based on the traditional magnetic tri-stable piezoelectric energy collector model, proposes a tri-stable piezoelectric energy harvester (TPEH+DEM) model with two elastic amplifiers which are installed between the U-shaped frame and the base and between the fixed end of the piezoelectric cantilever beam and the U-shaped frame respectively. Based on Hamilton principle, the motion equation of electromechanical coupling of TPEH+DEM system is established, and the analytical solutions of displacement, output voltage and power of the system are obtained by harmonic balance method. The effects of the mass of elastic amplifier, spring stiffness, magnet spacing and load resistance on the dynamic characteristics of energy harvesting of TPEH+DEM system are analyzed. The result shows that there are two peaks in the response output power of TPEH+DEM system in the operating frequency range. By adjusting the mass and stiffness of the elastic amplifier reasonably, the system can move into the inter-well motion under low external excitation intensity, and produce high output power. Compared with the traditional model which only has an elastic amplifier on the base of piezoelectric energy harvester, TPEH+DEM model has better energy harvesting performance under low frequency and low intensity external excitation.

Analysis of Dynamic Characteristics of Tristable Exponential Section of Piezoelectric Energy Harvester

“…It has the advantages of a simple structure, a small size and high energy efficiency performance and is widely used in wireless sensor networks, remote monitoring devices, the low power consumption of devices and other scenarios [1][2][3]. By harvesting vibrational energy in the environment, microelectronic devices can be self-powered, reducing or eliminating the need for conventional battery replacement [4], thereby reducing device maintenance costs and increasing device reliability and lifetime. Therefore, harvesting energy directly from the environment is a perfect solution for powering microelectronic devices in the future and has great value in research and application [5,6].…”