Dielectric Loss and Thermal Effect in High Power Piezoelectric Systems

Abstract Temperature rise is the main limiting factor that affects the performance of high power piezoelectric systems. Significant decrease of electromechanical conversion efficiency near the series resonance frequency results in more serious heating, which cannot be explained by the classical model. To understand the loss and heating mechanisms of transducers under actual operation conditions, we have systematically studied the dielectric loss. A series resistance is proposed in the equivalent circuit model to characterize the influence of dielectric loss. The active power and temperature rise of the transducer are measured under different conditions. Experimental results verify that our model can accurately quantify both mechanical and dielectric losses, and clarify that the dielectric loss is mainly responsible for the decrease of the efficiency and the thermal effect of the piezoelectric stack. Different from previous researches, we indicate that the dielectric loss is mainly related to the input current but not the applied voltage. This investigation could guide the design and control of high power piezoelectric systems.