Finite element simulation of piezoelectric transformers

Citation
T. Tsuchiya et al., Finite element simulation of piezoelectric transformers, IEEE ULTRAS, 48(4), 2001, pp. 872-878
Citations number
14
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Optics & Acoustics
Journal title
IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL
ISSN journal
0885-3010 → ACNP
Volume
48
Issue
4
Year of publication
2001
Pages
872 - 878
Database
ISI
SICI code
0885-3010(200107)48:4<872:FESOPT>2.0.ZU;2-Q
Abstract
Piezoelectric transformers are nothing but ultrasonic resonators with two p airs of electrodes provided on the surface of a piezoelectric substrate in which electrical energy is carried in the mechanical form. The input and ou tput electrodes are arranged to provide the impedance transformation, which results in the voltage transformation. As they are-operated at a resonance , the electrical equivalent circuit approach has traditionally been develop ed in a rather empirical way and has been used for analysis and design. The present paper deals with the analysis of the piezoelectric transformers ba sed on the three-dimensional finite element modelling. The PIEZO3D code tha t we have developed is modified to include the external loading conditions. The finite element approach is now available for a wide variety of the ele ctrical boundary conditions. The equivalent; circuit of lumped parameters c an also be derived from the finite element method (FEM) solution if require d. The simulation of the present transformers is made for the low intensity operation and compared with the experimental results. Demonstration is mad e for basic Rosen-type transformers in which the longitudinal mode of a pla te plays an important role; in which the equivalent circuit of lumped const ants has been used. However, there are many modes of vibration associated w ith the plate, the effect of which cannot always be ignored. In the experim ent, the double resonances are sometimes observed in the vicinity of the op erating frequency. The simulation demonstrates that this is due to the coup ling of the longitudinal mode with the flexural mode. Thus, the simulation provides an invaluable guideline to the transformer design.