Optimized design of self-powered SSHI interface circuit for enhanced vibration energy harvesting

Vibrational energy in ambient environment can be transformed into electrical power through piezoelectric energy harvesters and using synchronized switch harvesting on inductor (SSHI) techniques can significantly improve energy extraction efficiency. To enhance energy harvesting efficiency, this study proposes an efficient self-powered parallel SSHI (ESP-PSSHI) interface circuit. It enhances the passive peak detection switch, simplifies the circuit topology, reduces switching delay, and minimizes the ‘second inversion’, contributing to increased energy harvesting efficiency. To improve the impedance-matching characteristics of the circuit, the proposed circuit is combined with a DC-DC converter module and finally, a stable electrical output is achieved. The performance of the ESP-PSSHI circuit in power generation is analyzed through simulation and subsequently verified via experimentation. Experiments show that the maximum output power of the ESP-PSSHI circuit is 2.42 and 1.16 times higher than the output power of the standard energy harvesting circuit and self-powered parallel SSHI (SP-PSSHI) circuit, respectively. Through capacitor charging experiments, it is concluded that the output power of the optimized ESP-PSSHI circuit is 1.5 times the output power of the LTC3588-1 circuit.