Modeling and Experimental Verification of the Power Transfer and Thermal Characteristics of Piezoelectric Transformers Subjected to Combined Mechanical and Electrical Loading

S. Tuncdemir[1], W.M. Bradley[2]
[1]Solid State Ceramics, Williamsport, PA, USA
[2]QorTek, Williamsport, PA, USA

A piezoelectric transformer allows purely mechanical transfer and scaling of electrical energy via simultaneous utilization of both the direct and converse piezoelectric effects. This mechanical energy transfer enables a wide range of functional differences from typical magnetic-based electrical power transformers. Comparing to their electromagnetic counterparts, piezoelectric transformers are highly efficient and can have significantly high power density within reduced operating volumes. However, they need to be operated at resonance, which results in a complex non-linear system that requires significant design and analysis for effective system integration. In order to aid in the development of such high efficiency, high power throughput piezoelectric transformers we have developed a realistic COMSOL Multiphysics model and a range of experimental test setups for empirical verification. The model is capable of coupling both mechanical and electrical loads to the piezoelectric transformer, thus enabling examination of the thermal effects from the associated losses in the device. In this work, we are interested in the analysis of the piezoelectric devices at high power density and high frequencies, which will increase thermal loads generated by the device. Additionally, the model is capable of studying various environmental parameters such as dynamic electrical loading, mechanical and thermal effects from system packaging, and variations of input conditions.