Frequency and load effects on rectifier bridges and active circuits on mechanical energy harvested using piezoelectric materials
Résumé
Today, with the worldwide surge in the price of oil, the energy issue has become an important topic and the possibility of exploiting ambient energy is receiving renewed attention. Thus in this study, we are interested in the devices of recovery of piezoelectric energy of vibration whose final objective is to study the consumption bridge of the diodes and to compare it with the active circuits. The idea is first to extend the life of the battery. Then a second time makes the sensor completely autonomous from an energy point of view.
In this work, we will study the useful characteristics of the diode. For the sake of clarity and under what conditions it can be used, we will refer to the characteristic quantities presented by the manufacturer. Each parameter is defined for specific conditions of use. These conditions are specified and correspond to the measurement method used. In addition, we will focus on studying power dissipation in diodes in a range of frequencies, and the possibility of replacing the diode bridge with another active circuit as LTC3588-2 and LT4320 in certain conditions consume less energy than diodes. The open circuit tests performed on the transducer allowed us to evaluate the average power recovered at 1.5 mW on an optimal load resistance of 20 KW. The signal provided by the transducer was then shaped by simulation. For this, the characteristics of the real diodes of the series 1 N 400X were used, and with the capacitor of 50 µF, a power of 1,41 mW was obtained on an optimal load resistance of 18,5 KW. The management circuit used is a full-wave rectifier in its voltage doubler topology and with the obtained results, its efficiency is evaluated at 35 %.