The Equivalent Circuit Model Of Radial Vibration Mode Piezoelectric Transformer And Its Application

Comparing with conventional electromagnetic transformers, piezoelectric transformers (PTs) have many advantages, such as compact volume, non-flammability and non-electromagnetic pollution. PTs have potential application in many fields.The equivalent circuit model is very helpful in the PTs'design process. However, the study on the equivalent circuit model for the radial vibration mode PTs is less, and lack of systematicness. According to this problem, in this research work, the characterization and modeling of the radial vibration mode PT have been studied and developed. Based on the piezoelectric equations and wave equations, the physics-based equivalent circuit model of radial vibration mode piezoelectric transformers is derived in detail. The parameters used in this model are also derived. The deviations between calculated and measured values of the equivalent circuit parameters are in the acceptable range.In this thesis, a design procedure is also proposed for designing a PT that can match to specific application. This procedure includes selection of PT materials, determination of geometries and the number of layers of the PT. A radial vibration mode PT sample based on this design process is fabricated. The performance of the PTs is carried out, including load characteristic and frequency characteristic of step-up, efficiency characteristic and so on.Then apply the PT to a 12V 20W AC-DC converter. A corresponding circuit is designed, the printed circuit board is debugged and tested experimentally. The results show that the converter using this PT can achieved the requirements.