Finite element modeling of ring-shaped piezoelectric transformer

Abstract

In this work, we developed a finite element package to investigate the dependence of electromechanical coupling coefficient on ring-shaped piezoelectric transformer parameters, and proposed how to design the transformer in achieving optimum efficiency using the ceramic PZT-5H as an application. The ring transformer firstly used full driven electrode to observe piezoelectric vibration characteristic with varying the ring dimensional (structural) parameters. Then, with the optimized ring parameters, electrode layout was designed in accordance to the distribution of electrical potential within the ring transformer, where both alternating and non-alternating electrode layouts were considered. From the calculation, results showed that the piezoelectric vibration characteristic strongly depends on the ring-shaped transformer dimension. Specifically, with increasing piezoelectric ceramic thickness and the width between inner- and outer-ringradius, the resonance frequencies of the transformer decrease. On the other hand, in terms of the electrode layouts, the alternating electrode was a better choice in obtaining desired resonance frequency mode, as it provides larger electromechanical coupling coefficient than the non-alternating electrode. These results are in agreement with previous experimental investigation, where applicable. Copyright © Taylor & Francis Group, LLC.