Synergy of Wind Energy Harvesting and Synchronized Switch Harvesting Interface Circuit

Abstract

Due to the complex aero-electro-mechanical coupling involved in wind energy harvesting systems, power enhancing efforts in the literature are mostly devoted to structural modifications while the interface circuit is simplified to a resistive ac load. Yet the ac outputs are not applicable for practical usage. In this paper, we study the dynamics and dc power generation of galloping energy harvester. In particular, the enhancement of wind power extraction using the synchronized switching harvesting on inductor (SSHI) power conditioning circuit is emphasized. Analytical solution of the steady-state mechanical and electrical responses with the SSHI interface is derived explicitly and validated with wind tunnel experiment and circuit simulation. The performance of SSHI interface is compared to that of a standard bridge rectifier interface circuit. It shows that the SSHI interface achieves tremendous power enhancement in a weak-coupling system, and higher wind speeds render more significant power enhancement. Moreover, given the same wind condition and output power requirement, a system connected to the SSHI uses much less piezoelectric material compared to that connected to the standard circuit. With a weak-coupling harvester operating at a wind speed of 7 m/s, the SSHI can harvest up to 143% more wind power than the standard circuit.