| Summary: | 碩士 === 國立臺灣大學 === 機械工程學研究所 === 105 === Conventional piezoelectric cantilever beams use the strain generated by vibration to generate electricity. However, these harvesters have a disadvantage to being difficult to adapt to the vibration of the environment because the width of the cantilever beam harvesters are very narrow. It is to say that the efficiency of collection is low when the vibration frequency deviates from the resonant frequency. To improve this phenomenon, a V-shaped double-beam piezoelectric vibration energy harvester using a characteristic of the two-degree of freedom to narrow the distance between the first two resonant frequencies is developed in this thesis. The results show that for the V-shaped cantilever beam harvester, the first resonant frequency becomes larger and the second resonant frequency becomes smaller when the angle becomes larger with the same resistance. The magnification of the two resonant frequency changes form 5.4 times to 2.67 times when the angle changes from 0 to 90. Finally it becomes 1.33 times when the angle is 180.
In addition, this thesis also introduces two different series circuit, one is called direct connection, and the other is called reversed connection. Two kinds of series circuit will have different effects on the output voltage. The experiment results show that the direct connection will increase the output voltage in the first mode and decrease the output voltage in the second mode. On the other hand, the reversed connection has the opposite effect. Besides, the experiment results also show that the peak value of the voltage in the first mode decreases with the increase of the angle from 0 to 180. On the contrary, the second mode will increase when the angle increases
|
|---|
