Study Of Impact-induced Piezoelectric Wind Harvesting Based On PVDF

As a clean renewable energy, wind exist everywhere in the world and its potential is huge. Piezoelectric harvester technology has great research and application value as it can convert the wind to electrical energy to drive low power consumption devices. PVDF is an ideal material that can applied to piezoelectric wind energy harvesting for its strong weatherability and good performance in dielectricity and piezoelectricity, so PVDF was chosen as piezoelectric material in this paper. Characteristics of new raised cantilevers was and simulated and applied to the impact-induced piezoelectric wind harvester based on PVDF.The model of triangular, inner-arc triangular and outer-arc triangular piezoelectric cantilever was analyzed and the result showed the inner-arc triangular cantilever can improve the strain distribution. Static characteristic, transient characteristic, impedance and model extraction of the three kinds of cantilever was analyzed by ANSYS, the result show great agreement with model analysis that the inner-arc triangular cantilever has the best output performance. Impact-induced PVDF piezoelectric wind energy harvester with wind restraint devices was designed and tested in this paper, the rotor was also modified.The feasibility that the wind restraint devices and the modification of the rotor can increase the wind speed was verified through experiments. Piezoelectric characteristic of the triangular, inner-arc triangular and outer-arc triangular cantilevers was studied and the result showed that the inner-arc triangular cantilever has the highest output power of 198 μW which is greater than the triangular cantilever’s 185 μW and outer-arc cantilever’s 156 μW, the result showed great agreement with the ANSYS simulation and model analysis. Working state of cantilever and output characteristic of array was also studied through experiment. Characteristic of output power was tested in the actual load of resistance and LED. The result showed 2 cantilevers in parallel connection can increase the output power to 282 μW in the case of matched impedance; 8 LEDs can be lighted by a single cantilever and 2 cantilevers in parallel connection can light the 8 LEDs brighter than the other way of connection, and that showed great agreement with the conclusion in case of matched impedance.