Research On Ultrasonic Power System Based On FPGA Electrical Engineering

With the continuous deepening of ultrasonic technology in various application fields,the demand for ultrasonic power supply as the energy provider of ultrasonic processing equipment is becoming more and more urgent,and research is also constantly progressing.Based on the current research of ultrasonic power supply,this paper combines digital control technology with Field Programmable Gate Array(FPGA)as the main control chip to study the digital control of ultrasonic power supply.The main research contents of this paper are as follows:(1)Take the ultrasonic transducer as the research object,analyze the load impedance characteristics,and establish a series inductance tuning matching model.Analyze the impact of two different power adjustment methods on the DC side and the inverter side on the efficiency of the power supply,and select the inverter side phase shift power adjustment method.Analyze and compare the advantages and disadvantages of various frequency tracking schemes in frequency tracking performance,and select a frequency tracking scheme based on phase-locked method.(2)In-depth research on ultrasonic power control and frequency tracking control technology.Among them,in the power control link,a detailed analysis of the phase shift pulse width modulation(PS-PWM)technology in the resonance state,combined with soft switching technology to reduce device losses,to achieve output power adjustment.In the frequency tracking link,in order to overcome the current slow tracking speed,the frequency tracking strategy of the variable-step digital phase-locked loop is finally determined to realize automatic frequency tracking.(3)According to the overall structure and control strategy of the ultrasonic power supply,design the hardware circuit and software control module of the ultrasonic power supply system.The hardware circuit mainly includes the main circuit,drive circuit,feedback circuit,AD conversion circuit,communication circuit,etc.The feedback circuit includes sampling circuit,signal amplification circuit,phase detection circuit,effective value detection circuit,and protection circuit;software control module mainly includes protocol Stack module,frequency search module,frequency tracking module,PWM pulse generation module and human-computer interaction module.Finally,use MATLAB to build a simulation model of the ultrasonic power supply system,and verify the power adjustment model and frequency tracking model of the power supply system respectively.The simulation results show that the designed system model can well realize the system output power adjustment and frequency tracking control.Then use FPGA to build an ultrasonic power experiment platform.The experimental results show that the system frequency tracking effect is good when the load changes,and it also verifies the correctness and feasibility of the variable step control strategy adopted in this article.