Parallel and Series Piezoelectric Circuit Energy Harvesting

This article introduces an optimized piezoelectric energy harvesting circuit employing a switching strategy with two resonant circuits based on the Synchronized Switch Harvesting on Inductor (SSHI) architecture. The first circuit, P-SSHI, operates in parallel, while the second, S-SSHI, operates in series. Each circuit independently enhances the efficiency of piezoelectric energy harvesting. Integrating these circuits significantly reduces energy dissipation during the process. In the P-SSHI stage, an inductor L connected in parallel accelerates the charge and discharge of the piezoelectric transducer's intrinsic capacitor. Subsequently, in the S-SSHI stage, the energy stored in inductor L is effectively utilized. The circuit's performance was evaluated through simulations at various frequencies, showing power outputs 3.8 times higher compared to a reference Bias-Flip technique circuit within an operational frequency range of 5 Hz to 30 Hz.