An efficient parallel SSHI rectifier for piezoelectric energy scavenging systems

Today green energy plays an important role in human life; thus, many methods have been used to harvest green energy from the surrounding environment for the service of humankind. One of the most popular methods involves the use of a piezoelectric (PE) material to harvest energy from vibration sources. A PE energy scavenging system has two functional sections: a transducer, which converts potential energy into electrical energy; and an electrical interface, which is used to manage this electrical energy. One of the most important parts of the electrical interface is a rectifier, such as an AC-DC converter. This paper proposes a new control scheme for an efficient parallel rectifier based on a synchronized switch harvesting on inductor (SSHI) process; the inductor is parallel with an active full-bridge rectifier. The proposed control scheme circuit helps parallel SSHI rectifier can significantly increase the amount of power extracted from PE material. The parallel inductor enables the voltage across the internal capacitor of the PE material to be flipped instead of uselessly discharged every half cycle. Furthermore, an active full-bridge rectifier is used instead of a passive rectifier to reduce the threshold voltage of the passive diode. The simulation results show that the proposed rectifier has a power conversion efficiency of more than 92% and can extract four times more energy than a active full-bridge rectifier.