Self-Powered Extensible S-SSHI Based on RC Differential Circuit for Piezoelectric Energy Harvesting

At present, most piezoelectric energy harvesting (PEH) interface circuits are non-extensible only a single piezoelectric transducer (PZT) can be used or extensible at the expense of power consumption, component cost and volume. However, at a lower cost, the simultaneous energy harvesting by multiple PZTs under the same vibration source can more effectively increase the electrical energy supplied to the load. Hence, a self-powered extensible serial synchronized switch harvesting on inductor interface circuit based on RC differential circuit (SPEDS-SSHI) for piezoelectric energy harvesting is proposed in this article. It is implemented by reducing the number of switches required for the single piezoelectric unit and improving the reuse of components. The theoretical simulation demonstrates the effectiveness of the proposed circuit. The results show that the SPEDS-SSHI circuit can simultaneously harvest energy from multiple PZTs with any phase difference. The maximum harvested power of the proposed circuit for single PZT is 4.6 times that of the SEH circuit.