Piezoelectric actuators applied to neutralize mechanical vibrations

Abstract

Piezoelectric actuators are widely used in smart structural systems to actively control vibration and noise, and to enhance performance. Because of the highly capacitive nature of these actuators, special power amplifiers, capable of delivering high currents, are required to drive these systems. In this paper, a study to reduce the reactive energy that is necessary in such systems is carried out. This is accomplished by associating the actuator with its capacitive characteristic circuit. Also, non-idealities of the circuit performance are addressed, along with theoretical limits regarding possible power savings and practical difficulties in achieving them. The proposed converter introduces energy to correct the difference of phase between current and voltage that is supplied to the piezoelectric transducer (PZT) actuator. This process is optimized by the introduction of reactive power to the characteristic process of the PZT’s actuator circuit. Therefore the system is supposed to present an electric characteristic that is close to resistive, and is not capacitive any more.