Fixed Frequency Point of the Admittance Characteristics of Piezoelectric Transformer with Different Loads

Abstract

Piezoelectric transformer is a new type of transformer whose input and output characteristics often change with the load and cannot be maintained in a stable state. This work uses multiphysics coupling simulation method to study the impedance–frequency characteristics of single-layer rectangular piezoelectric transformer under different loads. Results show that the admittance–frequency curves under different loads have an intersection point, that is, the admittance fixed point. Compared with that in other working frequencies, the input power of the piezoelectric transformer working at the "intersection" frequency remains stable and does not change with the load.