Flexible Multi-modal Piezoelectric Energy Harvester with Hourglass Beams for Power Generation under Breeze Vibrations

Breeze vibration poses serious hazards to power transmission lines. Anti-vibration hammers are widely used to counteract the impact of breeze vibration. However, few have utilized the vibration energy of the anti-vibration hammer, the harvesting of which can not only mitigate shock of transmission lines, but also provide power sources for distributed sensors in the transmission sector of the smart grid. In this paper, a flexible multi-modal piezoelectric energy harvester (FMPEH) mounted on the anti-vibration hammer is proposed, featured by multi-segment hourglass beams to extend the effective beam length and achieve multi-modal response, jointly enhancing output power in the low and wide frequency range. Moreover, FMPEH is of planar structure, ensuring the lightweight, compact, and application-friendly attributes. The mass of a single FMPEH is only 1.35 grams. In mimetic field energy harvesting tests on the anti-vibration hammer, results show that the single FMPEH generates 12.96 V and 6.17 μW on 6.7 MΩ resistance under the breeze vibration condition, corresponding to 103.68 V and 49.36μW for the integral FMPEH array. Based on the 50% bandwidth criterion, the effective bandwidth is 18.5-25 Hz. The design and application of FMPEH effectively combines energy harvesting and shock mitigation in the power transmission industry, with potentially wide applications in future smart grid transmission systems.