Maximum power generation in a piezoelectric pulse generator

This investigation presents and discusses maximization techniques for a high-power piezoelectric pulse generator. Maximizing the piezoelectric generator´s output power is done by maximizing the product of generated voltage and output current. The maximization methods are derived from the mechanical and electrical models of the generator and provide design guidelines as to the geometric dimensions of the piezoelectric material and circuital conditions that will produce maximum power in the device. The theoretical results show the peak stack voltage to increase with an increasing thickness to area ratio of the piezoelectric material and with increasing applied force. However, in contrast to the peak output voltage, the peak output current increases with the decreasing of thickness to area ratio of the material. In addition to the physical dimension, the peak stack current increases as the value of the antenna inductor decreases. The output power of the piezoelectric generator, which is the product of output voltage and current, linearly increases with the thickness to area ratio. This result is due to the fact that the output voltage is larger comparing to the output current. Experimental results are also given to verify the theoretical results and represent the performance of several types of piezoelectric materials with different thickness to area ratios. The experimental results show good agreement with theoretical predictions. The results also show the peak power output of the experimental generator ranging from 7 to 28 kW with a corresponding power density from 9 to 173 kW/cm³.