Modeling and Analysis of a Large Stroke Tristable Vibratory Energy Harvester

Abstract

In order to magnify the responding frequency band of the energy collector under lower excitation, this paper constructs a tristable structure using four inclined springs, achieving a larger stroke. On this basis, a tristable electromagnetic energy harvester is proposed. The dynamic formula is solved by the numerical integration method, and the dynamic characteristics and current output characteristics of the system are analyzed. At the same time, for output power, the ratio of stiffness coefficients of the system spring was researched. It was found when the ratio of stiffness coefficients of the spring was 2/3, it would cause the potential energy function curve to be asymmetric. Compared to a symmetric system with a ratio fixed 1 of stiffness coefficients of the spring, the average output power increased by about one tenth. The research results indicate the proposed tristable energy collector can achieve energy collection under low amplitude and low-frequency excitation.