A dual-effect solution for broadband piezoelectric energy harvesting
Bao Zhao, Jiahua Wang, Junrui Liang, Wei‐Hsin Liao
Abstract
Literature has shown that the bandwidth of a piezoelectric energy harvesting (PEH) system can be effectively broadened by introducing nonlinear mechanical dynamics. However, when connected to a practical PEH interface circuit for ac-to-dc conversion, the bandwidth improvement will be impaired because of the electrically induced damping effect. On the other hand, there is another bandwidth broadening solution, in which the resonant frequency is tunable to some extent by carrying out the phase-variable synchronized switch (PVSS) control in practical interface circuits. This Letter reports a synergistic design by combining these two mechanisms toward a dual-effect broadband PEH solution. The theoretical model of this nonlinear and electromechanically coupled system is derived. The experimental result shows that, by introducing the PVSS control to a PEH system, which is composed of a monostable piezoelectric cantilever beam and a practical synchronized switch interface circuit, its bandwidth can be broadened by 18.7%. This dual-effect solution incorporates two bandwidth broadening mechanisms toward practical broadband PEH systems.