206 圧電コンポジットを利用した振動発電装置のエネルギー変換効率に関する考察 : 第四報,振動入力エネルギーと電気系のエネルギー消散の実験的評価(セッション7 エナジーハーベスティング)

Abstract

In the previous authors' study, the vibration energy harvester of the piezoelectric bimorph cantilever type was proposed for vibration condition monitoring applications of rotating machinery. Proposed energy harvester consists of the surface bonded two Macro-Fiber Composites (MFCs). In this study, energy transfer efficiency was derived from the energy balance equation during the natural period of the proposed vibration energy harvester. The maximum AC power through 114.3 Kilo-Ohm resistor which includes instrument internal resistances experimentally obtained 242.07 microwatt when subjected to vibration source input magnitude of 0.71 (mm/s rms) at the resonant frequency of the harvester (29.42 Hz). The impedance matching between MFCs and the electrical resistive load was effective for maximizing AC power transfer of the vibration energy harvester. Estimated energy transfer from mechanical system to electrical system shows the agreement with the experimentally evaluated generating power during the natural period of the vibration energy harvester with about 13 (%) difference. Estimated energy transfer efficiency was about 33 %.