Efficiency enhancement of a piezoelectric energy harvesting device in pulsed operation by synchronous charge inversion

This paper presents a new application of the 'Synchronized Switch Harvesting on Inductor' (SSHI). This nonlinear technique results in a significant increase of the electromechanical conversion capability of piezoelectric materials. Previous studies have shown the interest of this technique on steady state excited structures equipped with piezoelectric elements where the harvested power may be increased nearly tenfold compared to the standard technique. It is herein demonstrated that this technique is also very effective for pulsed excitation. It is shown that the SSHI technique increases the harvesting process efficiency between 250 and 450%, depending on the electromechanical coupling coefficient of the structure.