Wideband energy harvesting for resonant piezoelectric devices

In this paper, an active energy harvesting technique for a spring-mass-damper mechanical resonator with piezoelectric electromechanical coupling is investigated. The model of a piezoelectric dynamic system is built, and the active energy harvesting technique is developed. It is shown that the active energy harvesting technique can effectively enable impedance matching for a dynamic electromechanical system for all frequencies. Theoretically, the harvested power can be the maximum possible value for all excitation frequencies. However, in actual implementation, the power electronic circuit efficiency will add additional limitations to the amount of power harvested. A power electronic full-bridge converter is built to implement the technique, and experimental results show that the active technique has significant advantages over other techniques at off-resonance frequencies.