Adaptive active piezoelectric energy harvester

For traditional piezoelectric energy harvesters, the harvested power is very low in the non-resonant frequency. In order to solve the problem, a new active piezoelectric energy harvester is designed. The electromechanical coupling model and the equivalent electrical model of the piezoelectric dynamic system are built. The adaptive active piezoelectric energy harvesting technology is investigated, and an analytical expression of an optimal control voltage harvested the maximum power is derived. Finally, an adaptive active piezoelectric energy harvesting circuit which can achieve this optimal control voltage is proposed. Experimental results reveal that the adaptive active piezoelectric energy harvester can significantly improve harvested power in the broadband. Therefore, it can be used in the energy supply field for the MEMS, WSN and embedded systems.