New Adaptive A Capactiance Circuit for Magnetostrictive Energy Harvesting

Vibration energy harvesting by magnetostrictive materials using multi-switch circuit with adaptive capacitance is a new harvesting technique in which approximately the whole con-verted energy by smart patches can be extracted. This technique is worked based on imped-ance matching between the harvesting circuit and active elements in resonance condition. In the proposed technique a magnetostrictive layer is attached to a vibrating structure wound by a pick-up coil, in which the coil is connected to a set of capacitors with controller switches. For different vibration frequencies, the desired capacitance for electrical resonance in the circuit can be provided. Therefore, resonance condition is kept for each frequency and the whole converted energy especially the stored portion on the pick-up coil can be extracted. The electronic switches are controlled by a microcontroller in which frequency measurement and relevant calculations to have desired capacitance in the circuit are managed. A binary number with corresponding digits on the switches number is the output of microcontroller and each digit controls relevant switch. The proposed technique is modelled numerically and the results show a remarkable increase in the harvested energy rather than other methods

کلیدواژه ها:

mechanical vibrations ، energy harvesting ، magnetostrictive materials ، impedance matching.