Study On The Driving Power Of Piezoelectric Ceramic Based On Charge Feedback Control

Driving technology with piezoelectric actuators plays an important role in micro drive systems of micro/nano level.Due to the advantages of small volume,fast response and high resolution of displacement,piezoelectric actuators are the ideal driving devices for the driving technology of micro/nano level.Because piezoelectric actuators should work with the driving powers,it is the essential parts of the micro driving technology and the key factor to improve the drive accuracy.Most of piezoelectric ceramic drive power supplies on the market work in the linear mode,which neglected the hysteresis nonlinearity of piezoelectric.To compensate the hysteresis nonlinearity and improve the drive accuracy,a novel driving power of piezoelectric ceramic was designed with charge feedback control.The proposed driving power was powered by a battery of 24V.Firstly,the voltage was raised to a fixed voltage of 160V.The output voltage of the pre-stage was generated by DC/AC half-bridge inverter,and the output DC bias voltage was realized by the post-stage DC/DC step-down circuit.The two voltages were superimposed to meet the requirement of driving power.The pre-boost circuit used the Boost circuit and PI regulation to realize closed loop control.The post-stage DC/AC adopted the half-bridge inverter topology and the bipolar SPWM control strategy to design the voltage peak closed-loop control system.The post-stage is connected by the pre-stage circuit in parallel,and the latter DC/AC output is separated by a 1:1 transformer,which ensured that the inverter output voltage and the post-stage DC output can be effectively and rationally.After simulation in MATLAB environment,the system parameters were updated to improve the system performance.Considering the hysteresis nonlinearity of the piezoelectric actuators,the relationship between the input charge and output displacement were analyzed,and a charge feedback control was designed for driving power of piezoelectric ceramic.The output displacement of piezoelectric actuator can be calculated in the control system.The DC output of the post-step step-down circuit was updated by the PI regulation,and the output amplitude of the post-stage inverter circuit automatically followed the output voltage of the step-down circuit.Hardware circuit was designed based on theoretical analysis and simulation verification.System software was developed with NI CompactRIO system.The experimental platform was setup with the piezoelectric stack actuator(model.QDS-14×14×24).Experimental results indicate that the proposed driving power with charge feedback control can effectively compensate the hysteresis nonlinearity of piezoelectric stack actuator and improve the drive accuracy.