Synchronized triple bias-flip circuit for piezoelectric energy harvesting enhancement: Operation principle and experimental validation

Abstract

The power conditioning circuit plays an important role in a piezoelectric energy harvesting (PEH) system. Sophisticatedly designed circuit can increase the harvesting capability by several times. The synchronized multiple bias-flip (SMBF) model generalizes the performance of existing interface circuits and offers prospect for future circuit evolution. Among all ideal SMBF derivatives, the parallel synchronized triple bias-flip (P-S3BF) circuit makes the best compromise between cost and effectiveness. This paper introduces a practical implementation of P-S3BF. It is realized by an inductive current-routing network, which is controlled by six MOSFET switches. The steady-state operation principle towards PEH enhancement is analyzed in detail. The transient behavior is also illustrated for highlighting the adaptive feature of the new circuit. Both theoretical and experimental results show that, under the same harmonic displacement excitation, the prototyped P-S3BF circuit can increase the maximum harvested power by 24.5% compared to the cutting-edge parallel synchronized switch harvesting on inductor (P-SSHI) circuit, and 287.6% compared to the standard bridge rectifier circuit.