PARAMETRIC AL DESIGN OF A PIEZOELECTRIC ENERGY HARVESTER

摘要

In recent years trend toward little portable tools has affected technology obviously. So micro electro mechanical systems sound proper options because of their size and ability. To supply the energy of these devices batteries are not ideal candidates as they have life time limitations, relatively heavy weight and also they are not cost effective in long time. Piezoelectric vibration energy harvesters are the most common approaches to support micro electromechanical systems. They can use vibrational energy of different sources in the ambient to generate the required power, so are perfect to power remote applications, such as parts of wireless sensor nodes. In this research a piezoelectric energy harvester beam has been simulated and a parametrical study has been performed to analyze the effect of different accelerations and frequency on the system. Results indicate that the increase of acceleration leads to higher harvested power and also higher voltage. This means that the higher acceleration has the benefits of better system's efficiency but it should be also considered that higher accelerations require stronger system to be durable. Increase in frequency leads in increase in voltage and both of mechanical and electrical powers, when the frequency is less than the resonance frequency and in the frequencies higher than resonance of system, results in decrease of the voltage and electrical and mechanical powers consequently.