Performance enhancement in cable vibration energy harvesting employing inerters: Full‐scale experiment

Abstract

Harvesting cable vibration energy via electromagnetic dampers has been demonstrated as potential power supplies for wireless sensor networks or semi-active control devices. However, how the inerter enhances the energy harvesting performance of the electromagnetic damper when applied to a bridge stay cable remains largely unknown. This paper presents a full-scale experimental study on harvesting the vibration energy of a 135 m-long cable using an electromagnetic inertial mass damper (EIMD). The EIMD integrates an electromagnetic damper and an inerter. A numerical model of the cable-EIMD system was also established using Matlab/Simulink for performance analysis. In the free vibration test, the EIMD could achieve the peak output power of 61.52 W and average output power of 13.80 W, when the inerter and the load resistance are optimized, considering an initial displacement of 100 mm near the mid-span of the cable. The corresponding energy harvesting efficiency was up to 25.31%. However, the energy harvesting performance of the EIMD degrades under ultra-small-amplitude vibration conditions due to the overlarge parasitic damping induced by Coulomb friction. Besides, experimental data uncover a 53.08% increase of average output power due to the inerter used, while numerical results indicate a tremendous increase of output power up to 126.1% because of assuming low parasitic damping. The EIMD with the optimal parameters (inertance, damping coefficient, and load resistance) can provide superior energy harvesting performance owing to the energy amplification mechanism induced by the inerter.