Enhanced synchronized switch harvesting: a new energy harvesting scheme for efficient energy extraction

This paper presents a new technique for optimized energy harvesting using piezoelectric microgenerators called enhanced synchronized switch harvesting (ESSH). This technique is based on the concept of synchronized switch harvesting (SSH), a nonlinear technique developed for energy harvesting from structural vibration. Compared with the standard technique of energy harvesting, the new technique dramatically increases the harvested power by almost 300% at resonance frequencies in the same vibration conditions, and also ensures an optimal harvested power whatever the load connected to the microgenerator. Furthermore, the new technique (ESSH) in this paper can be truly self-powered; a self-powered circuit which implements the technique is proposed. In addition, the overall power dissipation for the control circuitry is relatively constant (only about 121 µW), which is more attractive especially at high excitation. Because the new technique (ESSH) in this paper can be truly self-powered, no external power supply is needed, making the system suitable for more application fields, especially in remote operation.