A Single-Stage Rectifier-Less Boost Converter Circuit for Piezoelectric Energy Harvesting Systems

In this paper, a single-stage rectifier-less boost converter circuit (SSRBC) for piezoelectric energy harvesting from ambient vibration was proposed. The proposed rectifier-less circuit acted as a boost converter to extract energy from a piezoelectric device (PD). It combined the conventional boost, buck-boost methods using two split inductors and a single filter capacitor. The proposed integrated circuit topology functioned in both positive and negative half cycles generated by the PD. In the proposed topology, inductors were invigorated by being enveloped with the current, which was produced by the PD through the switches. This facilitated active rectification of ultra-low AC (amplitude < 0.5 VP). Theoretical analysis, control strategies, simulation and experimental study, were presented. The proposed circuit was capable of converting a low amplitude AC voltage of 0.5 VP into 5.1 Vdc. The highest output power extracted by the proposed circuit was 281.1 µW, which outperformed existing circuits. It could potentially facilitate the advancement of vibration-based energy harvesting systems for low power demand applications such as sensors, quartz watches and portable charging devices.