Research on a rotary piezoelectric wind energy harvester with bilateral excitation

This paper describes a rotary piezoelectric wind energy harvester with bilateral excitation (B-RPWEH) that improves power generation performance. The power generating unit in the current piezoelectric cantilever wind energy harvester was primarily subjected to a periodic force in a single direction. The B-RPWEH adopted a reasonable bilateral magnet arrangement, thus avoiding the drawbacks of limited piezoelectric cantilever beam deformation and unstable power generation due to unidirectional excitation force. The factors affecting the power generation were theoretically analyzed, and the natural frequency and excitation force of the piezoelectric cantilever have been simulated and analyzed. A comprehensive experimental research method was used to investigate the output performance. The B-RPWEH reaches a maximum output voltage of 20.48 V_pp when the piezoelectric sheet is fixed at an angle of 30°, the Savonius turbine number is 3, and the magnet diameter is 8 mm. By adjusting the fixed angle of the piezoelectric sheet, the number of Savonius wind turbine blades, and the magnet diameter, the maximum voltage is increased by 52.38%, 4.49%, and 245.95%, respectively. The output power is 24.5 mW with an external resistor of 8 kΩ, and the normalized power density is 153.14 × 10^-3 mW/mm³, capable of powering light-emitting diodes (LEDs). This structure can drive wireless networks or low-power electronics.