A Self-powered Multi-input Bridgeless Series-SSHI Circuit for Piezoelectric Energy Harvesting

This paper presents a multi-input piezoelectric (PE) energy harvesting circuit, which integrates a Series Synchronized Switch Harvesting on Inductor (S-SSHI) and a Voltage Doubler (VD). The proposed circuit uses the VD topology to reduce the number of diodes used in the resonant loop of the S-SSHI circuit, and hence more power available for the load. Besides, the circuit adopts a parallel connection for multiple different PE transducers, in which an inductor and the VD are re-used to harvest the energy. It improves the inductor's utilization and reduces the complexity of the circuit. The circuit is self-powered and capable of starting even if the battery is drained. Discrete components prototyped the circuit with a cost-effective implementation. The measured results show that compared with full-bridge topology, the proposed circuit increases the power harvested from two different PE transducer three times at the same excitation condition.