Experimental and numerical assessment of a high-performance electromagnetic vibration energy harvester in a double-deck railway tunnel

This paper evaluates the performance of an electromagnetic vibration energy harvester for powering wireless sensor networks in railway tunnels. A field test was conducted in a double-deck railway tunnel, measuring vibrations as well as the mechanical and electrical responses of a prototype of the harvester during 139 passing trains. Numerical simulations have been carried out to estimate the harvester’s output performance, from which a good agreement has been reached when comparing the experimental and simulated induced voltages. Using the validated model and measured vibration data, the harvester’s performance adopting a fully frequency-tuned resonant system for different implementation locations, such as the tunnel wall and the rail, has been simulated. Cumulative electrical energy generated by the harvester for different locations is presented for the total period of railway-induced vibration measurements. Maximum cumulative electrical energies of approximately 1805, 0.52, and 7838 mJ have been estimated to be generated by the harvester when placed on the interior floor, the wall, and the rail, respectively, in about 9 h of operation.