Nonlinear Model and Experimental Verification of Bistable Hybrid Energy Harvester Based on Wheel–Rail Vibration

With the rapid development of rail transit, it is becoming more demanding to structural health monitoring (SHM) of long-span tracks. In order to ensure the safe operation of railway systems, it is crucial to supply power for wayside monitoring sensing devices. A hybrid piezoelectric-electromagnetic energy harvester (HPEH) based on wheel-rail vibration is designed to supply power for wayside monitoring sensing devices. The coupling model of control equation of hybrid energy harvester and wheel-rail dynamics is built to devote the relationship between the output power of hybrid energy harvester and external excitation signal. HPEH is fabricated and fixed onto the track wrist for harvesting the wheel-rail vibration energy for power supply of wayside monitoring sensing devices. By theoretical analysis, finite element modeling (FEM), and experiment validation, the maximum voltage of bistable HPEH reaches at either 150 or 260 Hz. The bistable HPEH has the output voltage 2.12 V and the output power of 266.4 mW. Field tests have validated that HPEH is applied to power supply of wayside monitoring sensing devices successfully by converting vibration energy into electrical energy. New multi-stable energy harvester has great prospects and reliability in the power supply to wayside sensing devices to long-term SHM of the railway system for promoting the intelligent sensing level of the track.