A bidirectional energy conversion circuit for piezoelectric energy harvesting and vibration exciting purposes

Abstract

Piezoelectric transducers can convert the mechanical energy into electrical one with their direct piezoelectric effect, or reciprocally convert the electrical energy into mechanical one with their inverse piezoelectric effect. Various applications were developed based on either of these two effects, for example, sensors and energy harvesters using the direct piezoelectric effect and actuators using the inverse piezoelectric effect. Yet, few of them have fulfilled the multi-functional purposes, which are useful in some application scenarios. This paper proposes a bidirectional energy conversion circuit (BECC) solution for the time-division energy harvesting and actuating purposes. The circuit topology is derived from the synchronized triple bias-flip circuit, which was formerly used for energy harvesting enhancement. The circuit topology and control logic for energy harvesting and actuating modes are discussed in details. Two designs are studied for investigating the potential applications of the BECC. In the linear piezoelectric structure, the BECC can be used to provide vibration excitation and then reclaim the vibration energy. Such time-division energy injection and reclamation can be used in some non-destructive structural health evaluations. The proposed BECC can be also used to realize the controllable orbit exciter in nonlinear piezoelectric energy harvesting systems. It is the first time to realize a compact and integrated orbit exciter and energy harvester by using a single interface circuit. Simulations and experiments are carried out for validating the performance of the BECC towards versatile engineering designs.