Research On New Ultrasonic Power Supply Based On DSP

With the continuous advancement of electronic technology,ultrasonic power technology has been rapidly developed,and widely used in industrial production.In order to obtain higher product quality,modern industry has put forward higher requirements on the working efficiency and intelligence of ultrasonic power supply Aiming at the problems of low frequency tracking accuracy,slow response,and poor power adjustment capability of traditional ultrasonic power,this subject designs a new ultrasonic power with DSP as the control core.Firstly,this paper analyzes the working principle of the piezoelectric transducer,builds an equivalent circuit based on electrical characteristics,and gives the operating characteristics of the transducer under resonance through impedance analysis,which provides a theoretical basis for the frequency tracking scheme.In this paper,the series resonance frequency of the transducer is selected as the system operating frequency.By comparing the matching effects of different circuits,LC matching is determined as the system matching circuit.Secondly,the overall plan of the ultrasonic power is established,and the AC-DC-AC mode is adopted as the main circuit topology.In terms of frequency tracking,a frequency tracking strategy combining the maximum current value method and digital phase-locking technology is used.The search for the resonance frequency is completed by the maximum current value method,and the digitally locked loop is used to phase-lock the searched resonance frequency to realize automatic frequency search and tracking.In terms of power adjustment,the DC side Buck circuit is used as the power adjustment scheme,and a double closed-loop power adjustment strategy is designed,which combines the PID control algorithm to achieve power adjustment.Finally,the hardware design and software design of the DSP control system are completed according to the overall plan.The hardware design includes: rectifier filter circuit,Buck circuit,inverter circuit and control system feedback circuit;software design includes: main program,A / D conversion program,frequency tracking procedures,power adjustment procedures,etc.Through the combination of software simulation and hardware debugging,the feasibility and rationality of the designed hardware circuit and control scheme are verified.Experimental results show that the designed ultrasonic power system meets the requirements of frequency tracking and power regulation.