Novel power conditioning circuits for piezoelectric micro power generators

Abstract

Low power devices promote the development of micropower generators (MPGs). This paper presents a novel power conditioning circuit (PCC) that enables maximum power extraction from a piezoelectric MPG. Synchronous rectification (SR) is employed to improve the PCC efficiency. A simplified model of the piezoelectric generator is developed for simulation. Performance of the proposed PCC is verified by PSpice simulation and experimental results. A maximum output power of 18.8 /spl mu/W has been extracted from a single piezoelectric MPG. Arbitrary waveform generator representation (AWGR) of the flexing piezoelectric membrane is also presented. The hardware AWGR enables research on the PCC without the need for the actual MPG heat engine or bulge tester used to flex the piezoelectric membrane, and also demonstrates the feasibility of cascading many MPGs to extract additional power.