Research On Piezoelectric Ceramic Drive Power Supply Based On Nonlinear Preisach Model

Piezoelectric ceramics(PZT)have been widely used in the microdisplacement field due to its advantage of high positioning accuracy,small size and strong anti-electromagnetic interference capability.The performance of micro-displacement system with PZT actuators depends not only on the actuators,it is also closely related to the performance of the driving power supply.In current research,the driving power supply of capacitive load in the current research is not designed in combination with the hysteresis characteristics of PZT.Therefore,it is of great significance to research a driving power source which is suitable for PZT actuators.In this dissertation,a driving power supply was designed for the load hysteresis characteristics of PZT.In order to simulate the hysteresis loop effect of PZT,the Preisach mathematical model is built.The nonlinearity of PZT and the time-dependent characteristics of model parameters are summarized.The requirements of driving power supply are analyzed according to the load characteristics and design criteria are proposed.For the contradiction between the output voltage stead y-state ripple noise and the power supply efficiency,the main power design scheme of the switch linear composite architecture is adopted.The output voltage of the pre-stage switching converter tracks the output voltage change of the driving power supply dynamically.Under the requirement of ensuring the output voltage of the driving power supply to meet the low steady-state ripple noise,the power consumption of the driving power supply is reduced.With the problem of voltage overshoot caused by excessive instantaneous charging current,a proportional current source is proposed as the current limiting circuit.The driving power output current limit value dynamically tracks the output voltage,and achieves the purpose of zero overshoot of the output voltage under the requirement of response speed.The problem caused by hysteresis loop effect is solved.With the problem of nonlinearity between the input voltage and output displacement of the model,and the time-varying of the model,the parameters fuzzy adaptive PID control strategy is adopted.The fuzzy controller adjusts the three control parameters of the PID controller online according to the characteristic parameters of the controlled object,and achieves better control effect than the PID control in dynamic performance.A prototype of piezoelectric ceramic drive power supply was built based on the above theoretical analysis.Steady-state performance test results show that the output voltage steady-state ripple noise less than 7 mV because of the switching linear composite architecture,the main circuit power consumption decreases by 57.1%,and the one-hour output voltage stability is less than 20 mV.the dynamic performance test results show that the output voltage maximum response time less than 85 ms,the overshoot is zero,and the fuzzy adaptive PID has better dynamic control than the traditional PID.The correctness of the theoretical analysis is verified by the above experimental results.