Maximizing the output power of a piezoelectric generator from the admittance measurement by selecting the rectification technique

AC-DC converters employed for harvesting power from piezoelectric transducers can be divided into linear (i.e. diode bridge) and non-linear techniques (i.e. synchronized switch harvesting on inductor, SSHI). Depending on the piezoelectric element, a non-linear technique can improve a significant percentage the power harvested. This paper presents an analytical technique based on the measurement of the impedance circle of the piezoelectric element to determine whether the diode bridge harvests a considerable percentage of the available power.