Strategy for enhancing the active harvesting of piezoelectric energy

This article proposes new methods for enhancing the active harvest of piezoelectric energy using the synchronized switch harvesting on inductor (SSHI) technique. It was experimentally confirmed that the energy harvested by the original synchronized switch harvesting on inductor technique was decreased by the suppression of the vibration amplitude, and this critical problem was solved by developing new control strategies, namely, switch harvesting considering vibration suppression (SCVS) and adaptive SCVS (ASCVS). The SCVS technique was designed to intentionally skip some of the switching actions of the original synchronized switch harvesting on inductor technique, while the ASCVS technique enables more flexible variation of the number of skipped switching actions. The skipping of the switching actions facilitates the recovery of the vibration amplitude produced by the excitation force, and the developed strategies thus maintain the vibration amplitude at the highest possible level, resulting in increased energy harvest. The results of the experimental implementation of the proposed strategies showed that they enabled the harvesting of as much as 10.5 times the energy harvested by the original synchronized switch harvesting on inductor technique. The ASCVS technique particularly enables flexible enhancement of the harvested energy under various vibration conditions.