Design and analysis of a scalable harvesting interface for multi-source piezoelectric energy harvesting

•Three scalable harvesting interfaces for multi-source piezoelectric energy harvesting (M-PEH) are proposed.•Theoretical analysis of these interfaces for M-PEH are conducted.•The results show the effectiveness of these proposed interfaces for MPEH.•Contribute to the development of M-PEH system with characteristics of multi-direction and broadband frequency.

Harvested power and operating frequency bandwidth of a piezoelectric harvester can be improved significantly by using multi-source piezoelectric energy harvesting (M-PEH). However, this M-PEH approach makes it more difficult to design an effective harvesting interface circuit. In this paper, three scalable harvesting interfaces for M-PEH are proposed: the scalable standard interface for M-PEH, the scalable Series-SSHI interface for M-PEH and the scalable SECE interface for M-PEH. These proposed scalable M-PEH interfaces, take advantage of the basic techniques of standard AC-DC, series-SSHI and SECE, and are capable of harvesting energy from multiple piezoelectric elements simultaneously. The theoretical derivations are conducted, and the experiments are performed with a good agreement between theory and experiment. Experiments utilizing two piezoelectric elements confirm the effectiveness of the proposed interfaces; they can produce twice as much energy as the typical single source piezoelectric energy harvesting (S-PEH) techniques, no matter what the piezoelectric voltage phase difference is. Finally, M-PEH exhibits significant bandwidth improvement and excellent scalability versus S-PEH.