Analysis and Experiments of a Pendulum Vibration Energy Harvester With a Magnetic Multi-Stable Mechanism

This work couples a magnetic multi-stable mechanism to a pendulum vibration energy harvester so as to widen its bandwidth, especially in low-frequency operation. Multiple stable points are formed by a movable permanent magnet installed on the pendulum and two fixed permanent magnets installed symmetrically on the base of the energy harvester. Thus, the pendulum can swing between the stable points at two sides, which causes large motion amplitude and power generation. In designing the prototype of the energy harvester, dynamical modeling and potential energy analysis are carried out to achieve a low threshold for snap through. An experimental setup is developed and a series of comparative experiments are implemented to investigate prototype performance. It is shown that the energy harvester with the fixed magnets can generate a noticeable normalized induced voltage at 0.7 Hz, while the energy harvester without the fixed magnets requires the excitation frequency of 1.0 Hz to reach a similar level. The electrical outputs varying with vibration acceleration and load resistance are also examined. In general, the experimental results verify the effectiveness of the proposed structure on enlarging frequency bandwidth. This work can provide a promising candidate of energy harvesting for low-frequency applications such as ocean wave.

Automated summary

This work combines a magnetic multi-stable mechanism with a pendulum vibration energy harvester to widen its bandwidth, especially in low-frequency operation. Experimental results demonstrate the effectiveness of the proposed structure in enlarging frequency bandwidth and provide a promising solution for energy harvesting in low-frequency applications such as ocean wave.