上海科技大学知识管理系统

In this paper, a novel ac/dc converter is proposed for low-voltage and low-power ac rectification applications. The proposed converter manages the energy harvested from microscale electromagnetic generators (MEGs). It integrates the conventional boost and buck-boost topologies with a shared inductor, a bi-directional switch, and two split filtering capacitors. The boost and the buck-boost topologies function in the positive and negative half input cycles, respectively. The inductor is energized by being shorted with the input source through the MOSFET channel without using the diodes. This enables active rectification of low-amplitude (below 0.7 V) ac voltages. Theoretical analysis, design considerations, and control method are detailed. A 40-mW circuit prototype, which converts a 0.4-V peak, 100-Hz ac voltage source to 3.3-V dc, is designed and tested to verify the proof of concept.