A high efficiency piezoelectric energy harvesting system

Nowadays, harvested energy from surrounding environment plays an important role in the human life. This green energy gradually replaced for traditional energy such as fossil energy. Several methods have been used to capture green energy from environmental source. One of the most popular method is using piezoelectric material to harvest energy from vibration source. A piezoelectric energy harvesting system include two sections: a transducer to convert potential energy to the electrical energy and an electrical interface to manage this energy. Normally, a rectifier and voltage regulator are two main components in the electrical interface. In this paper, a new high efficiency piezoelectric energy harvesting system is proposed to increase extracted power from piezoelectric. By using two synchronized switches, the extracted efficiency of the rectifier is double. Furthermore, the passive diode of the conventional rectifier is replaced by active diode to increase the conversion efficiency of rectifier. The simulation result show that the power extraction efficiency of the rectifier is 3.5 times that of the conventional full bride rectifier, and more than 93% of power conversion efficiency can be achieved. To completely piezoelectric energy harvesting system a Low-drop regulator (LDO) is used to regulate voltage at the output of rectifier. The LDO gets maximum 90% efficiency with 3mV voltage ripple. The overall efficiency of proposed system gets 83.3%.