Hammer Impact-Driven Power Generator Using Buzzer-Type Piezoelectric Energy Converter for Wind Power Generator Applications

Abstract

A novel hammer-impact-driven power generator that uses a buzzer-type piezoelectric energy converter (BPEC) for wind-power-generator applications was designed, and the dynamic motions and output characteristics were analyzed. As the active material, Sm0.025-Pb0.9625[(Mg1/3Nb2/3)0.71Ti0.29]O3 (Sm-PMN-PT)ceramic was used; this material has a high piezoelectric charge constant of 1100 pC/N and an electromechanical coupling factor of 58%. A rotational impeller triggered an impact between one end of the bar-type hammer, and, thereby, impact energy transferred to the BPECs. The manufactured power generator was tested from 50 RPM to 250 RPM, using the handmade evaluation system; it was able to operate with small impact force and greatly improved output performance as rotation speed increased. The maximum output of the generator was 10.4 W at a load resistance of 500 Ω and rotation speed of 250 RPM. For improvement of the output characteristics, the generators were arranged such that they could operate simultaneously. Moreover, the proposed model was applied to a Savonius–Darrieus turbine, and the output performance was evaluated at various wind conditions in a wind tunnel.