High‐Power‐Density Rolling‐Magnet Based Energy Harvesting from Transmission Lines

ABSTRACT With the increasing dependence of national development on power grids, a self‐powered grid security system is urgently needed for the long‐term safe operation of transmission lines. To provide sustainable power for the system, a rolling‐magnet‐based energy harvester (RMEH) is proposed by utilizing the mechanical energy in a rolling magnet, as triggered by the alternating‐current magnetic field from the transmission line. Due to the compact structural design and rapid magnetic‐field variation from the rolling motion, RMEH achieves an average power density of up to 128.5 W/m 3 and 0.14 W/kg in volume and mass, respectively, which stands far ahead of other reported studies so far. Furthermore, the trajectory of the magnet rolling is numerically calculated by kinetic equations, confirming a high degree of consistency between experimental and simulation results. Based on the theoretical analysis and experimental results, the effects of current amplitude and magnetic sheet thickness on the output performance are investigated. Moreover, RMEH can create a self‐powered smart grid security system with multiple functions including bird repelling, aviation obstacle indication, and wireless monitoring, demonstrating a broad prospect on the future grid security systems for transmission lines.