An Electromagnetic Tri-Stable Energy Harvester for Freight Train Condition Maintenance

The abundant vibration energy from freight train operation can be used to power a self-powered monitoring system. However, current research of this type focuses mainly on the utilization of longitudinal vibration. In this paper, a tri-stable electromagnetic vibration energy harvester that converts horizontal vibration energy into electrical energy is proposed for freight train system maintenance. The tri-stable state is realized by a limiting spring through a fixed magnet attraction. Theoretical analysis and experiments are carried out on the harvester. The experimental results show that the harvester’s operating bandwidth is skewed towards low frequencies, with a maximum output voltage of 4.26 V and a maximum peak-to-peak value of 8.68 V at an excitation frequency of 6 Hz and an excitation acceleration of 1 g. This proves that the harvester has the potential to be used as a source of power for self-powered systems for condition maintenance of freight trains.