Modeling and Verification of High-Power Piezoelectric Transducers

• Main Authors: Wen-Jong Wu, 吳文中
• Other Authors: Chih-Kung Lee
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/89727074163187984055

博士 === 國立臺灣大學 === 應用力學研究所 === 91 === Taking equivalent circuit model of traditional piezoelectric materials as the starting point, it was discovered during the course of this research that significant discrepancy exists between the theoretical prediction and the experimental data obtained from measuring the output of high-power piezoelectric transformers. A complete testing platform incorporates both electrical and mechanical testing for piezoelectric transfers under high-power driving condition were proposed and built. The newly developed testing platform provided us with an opportunity to test complete material electrical and mechanical parameters of piezoelectric transfers directly, i.e., the needs to create special piezoelectric specimen is diminished. This direct testing strategy for piezoelectric transformers could be used to evaluate the variations of material properties induced by different manufacturing processes. In order to test dynamical mechanical property of piezoelectric transformers under high-power driving condition, a quadrature homodyne laser Doppler interferometer and complete digital processing circuitry were built and used to test vibration velocities of piezoelectric transformers. The electrical and mechanical coupling properties related to measured vibration velocity on high-power driven piezoelectric transformer were also analyzed in detail. The theoretical model and parameters measured under low-power electrical test of piezoelectric transformer will also be verified and then be compared with the high-power and vibration velocity test. The vibration velocity testing will be used to independently determine piezoelectric and dielectric non-linear effects under high-power driven. An innovative isolation multi-layer complete modal actuating piezoelectric transformer design were also proposed and verified. All higher order vibration modes other than the desired operating mode is all canceled out with the modal filter concept implemented onto the desired piezoelectric transformer. With the newly design complete modal actuating piezoelectric transformer, resonant inductor-less inverter becomes possible. As high-efficiency and high step-up ratio of piezoelectric valid only near resonant frequency, the power amplifier and control method for high-power piezoelectric transformers testing needed to be designed carefully. The power amplifier design and control method will also be discussed based on the experimental results disclosed from this dissertation