Bi-Stable Vibration Power Generation System Using Electromagnetic Motor and Efficiency Improvement by Stochastic Resonance

Research on vibration energy harvesting using stochastic resonance has become an important research topic. A vibration energy harvesting system was developed using electromagnetic motors based on an obliquely supported bistable motion model consisting of a spring mass. After formulating the motion-governing equations of the proposed vibrating system and analyzing its potential energy performance, it was demonstrated that the system exhibits bi-stable vibration characteristics throughout its entire range of motion. To expand the vibration amplitude using the stochastic resonance phenomenon, a prediction formula for the periodic excitation frequency that causes stochastic resonance was derived using Kramer's rate. An experiment was conducted; the obtained results and predicted values of the excitation frequency agreed well and the validity of the prediction formula for the periodic excitation frequency of stochastic resonance was verified. It was confirmed that the proposed bistable vibration energy harvesting system reliably generated stochastic resonance by exciting random and periodic signals at the same time. The results of the experiment indicate that there was a significant vibration amplification effect, which significantly improved the vibration power generation performance.