Research And Design Of Piezoelectric Ceramic Power Amplifier Based On Three-level Topology

As a new type of micro displacement device,piezoelectric ceramic actuators have the advantages of small size,low susceptibility to electromagnetic interference,high resolution,fast response speed,and high output power density,making them ideal actuators.The performance of piezoelectric ceramics is determined by the output performance of power amplifiers.In the application of model vibration reduction systems,the effect of vibration reduction is directly related to the performance of piezoelectric ceramic driving power supply.In the vibration reduction system,piezoelectric ceramics need to output sufficient thrust to drive the model during vibration reduction;Low distortion of driving waveform,achieving precise and fast vibration reduction;In the stationary state of the model,the piezoelectric ceramic should be in a stable state.Therefore,there are requirements for piezoelectric ceramic driving power sources in terms of output power,voltage ripple,and harmonic distortion.This article focuses on the research and design of piezoelectric ceramic power amplifiers based on three-level topology.The main research content of this article is as follows:This article analyzes the current research status of piezoelectric ceramic driving power supplies and three-level inverters.Based on the characteristics and design requirements of each topology,a T-type three-level inverter circuit topology is selected as the main circuit,and the circuit topology structure and working principle are studied and analyzed.Analyze the working states of three levels and the voltage stress of the switch tube under the working state.Research the control strategy of the inverter circuit according to the requirements,adopt a dual carrier co directional amplitude shift modulation method,and provide the modulation process and corresponding switch states.Compare traditional two-level circuits with multi-level circuits,compare the magnitude of output harmonic distortion,and the voltage that switching devices need to withstand,to obtain the feasibility and advantages of three-level circuits.And studied some key technologies of piezoelectric ceramic driving power supply,mainly including midpoint balance problem,control system,filtering network,inverter soft switching technology,and studied and analyzed the circuit design of each part.An overall design scheme has been proposed based on the various indicators of the driving power supply.A piezoelectric ceramic power amplifier based on a T-type three-level inverter topology was designed and applied to the model vibration reduction system to achieve active vibration reduction of the model.Complete the hardware circuit design of the piezoelectric ceramic driving power supply for the T-type three-level inverter topology,including: AC-DC switching power supply,T-type three-level inverter circuit,FPGA control system circuit,LCL filtering circuit,DC voltage stabilizing circuit,overvoltage and overcurrent protection circuit.And a detailed design was made for the control system,which includes four parts: input signal acquisition,SPWM control signal generation,output voltage closed-loop,and upper computer communication.After theoretical analysis and design,a complete driving power supply was produced as an experimental platform,and its output performance was tested.Experiments were also conducted on output harmonic distortion,ripple,and stability.Through performance testing and data analysis,the driving power supply designed in this project can amplify the input signal by 100 times and output it under a piezoelectric ceramic load with an equivalent capacitance of 30 u F,with a frequency response range of 5-500 Hz.The driving power supply output voltage is 0-1000 V,and the maximum output current can reach 5A.The harmonic distortion of the output voltage is less than 2%,and the DC output ripple coefficient is less than 1%.In vibration reduction testing,it can achieve rapid vibration reduction.The driving power supply can operate stably for a long time and achieve the expected output performance.