This study proposes a novel piezoelectric energy harvesting (PEH) system achieving dual frequency up-conversion (FUC) for rotational motion. The system integrates a piezoelectric cantilever beam, two stoppers, and three magnets, all mounted on a rotation plate. Under centrifugal forces and magnetic repulsion, impact between the beam and stoppers excites high-order vibration modes, inducing FUC mechanism. A piecewise mathematical model is presented to describe the proposed PEH dynamic model. In addition, the influence of stoppers at different positions on the output voltage results is compared and discussed experimentally. The results demonstrate that the system exhibits significant dual FUC capability within the rotational speed range of 260 to 320 rpm, achieving a maximum peak output voltage of 4.754 V at a constant speed of 314 rpm.

PEH, stoppers, FUC