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, Sm-0.025-Pb-0.9625[(Mg1/3Nb2/3)(0.71)Ti-0.29]O-3 (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 omega 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.