Research On High Frequency Ultrasonic Power Supply Used For Cleaning

Now the market of industrial cleaning requirements is higher and higher, and it is very difficult for the general cleaning to do. Ultrasonic cleaning technology has been more and more widely concerned because of its good cleaning effect. Especially High frequency ultrasound technique has broad application prospects and high research value in precision instrument cleaning industries. The ultrasonic power supply is the core part of ultrasonic cleaning, its performance often determines the quality of ultrasonic cleaning.In this thesis, high frequency ultrasonic power supply system used for cleaning is studied and designed. First of all the working principle of the uncontrolled rectifier, Buck chopper, high frequency full bridge inverter circuit and select output circuit are analyzed. This thesis analyses the impedance characteristics of the transducer, and confirms the series resonant frequency as the working frequency of the system. Through the research and analysis of three kinds of matching networks, the LC type network is determined to match the tuning method.When the power supply works, the same phase of voltage and current can make the maximum output power, and the cleaning effect can be better. The design of half digital phase-locked loop can achieve frequency tracking. By using D trigger to identify the frequency changing direction, getting the size of the phase difference by XOR gate. DSP real-time updates the frequency of the inverter circuit to achieve the purpose of frequency tracking after collecting information and PI adjustment. The frequency tracking model is built by using PSIM simulation software, which verifies the correctness of the control method.Based on theoretical research, this thesis designs a prototype of the ultrasonic power supply that the inverter frequency is 770k, and gives the detailed calculation and selecting the parameters used in the prototype. Whereas the high frequency environment, designing the drive of chopper and inverter drive circuit, According to the system requirement, the sampling circuit, filter circuit and multi-output circuit are also designed in this thesis. And finally, the design and port assignment of the DSP chip TMS320F28335 is introduced.At last, the thesis tests this system design, and the inverter driver has a steep rising and falling edge in the actual test. The output waveform is good, automatic tracking is making, and achieving the same phase of output voltage and current. The overall power supply design has achieved anticipative target.