Analysis and design of power conditioning circuit for piezoelectric vibration energy harvester

Abstract

This study presents the design of a piezoelectric vibration energy generator with power conditioning circuit to power CMOTE wireless sensor node. The test result shows that the energy harvester produces a maximum AC output voltage of 3 V with an optimal resistive load of 200 Ω for 1.5 m/s 2 acceleration at the resonant frequency of 275 Hz. The output power from the energy harvester is 65.9 mW. The characterisation analysis of energy harvester without tip mass and effect caused by the addition of mass at different positions have been analysed. Additional mass reduces the device frequency to 21.5 Hz and improves the output voltage up to 3.632 V. A single-stage AC-DC power converter which integrates the rectification and boosting circuit is designed, simulated and implemented in hardware to extract the maximum power from harvester to attain higher efficiency. The designed circuit will operate at a minimum AC voltage of 0.5 V. The minimum output from the harvester is rectified, boosted to 7 V DC output and regulated to 3.3 V to power wireless sensor node. The conversion efficiency of the circuit is improved to 70.03% with reduced loss of 19.76 mW by size reduction.