The Research On The DSP-based Ultrasonic Power Supply Of Wide-frequency Output

Traditional ultrasonic power supply, especially applied by biological treatment ofultrasonic power, usually operated in a fixed frequency or power, which reduce the efficiencyof ultrasonic treatment greatly. But with the breakthroughs of ultrasonic transducertechnology constantly, as well as the application in industrial control of high performanceDSP chip, make the research and control of broadband ultrasonic power become possible bydigital control. Thus, the system integration can be improved greatly, and the various aspectsfunction of the system can be optimized.The studies and the design of broadband ultrasonic power supply based on DSP isproposed by this paper, and a high-performance32-bit floating-point DSP chip F28335isselected. It is mainly used in ultrasonic biological treatment systems. The optimal frequency isdetermined by the concentration of the biological treatment fluid,transducer load is switchedby DSP,which made the ultrasonic power supply operate in the optimal frequency,andfrequency tracking is realized by gathering the current and voltage of the load.The broadbandfrequency of ultrasonic oscillator array is used as ultrasonic transducer load, and the real-timeparameters of the ultrasonic oscillator array is be measured, and its matching inductancetuning matching and the matching of impedance matching transformer ratio are calculated. Interms of power supply design, the function of a wide range of frequency conversion andvoltage variable can be realized by the DC/DC, DC/AC two-stage circuit, so as to realizebroadband output, power adjustable ultrasonic of power supply. Buck switching power supplyis used by the front-end DC/DC, Voltage is given to DSP by matrix keyboard, which used torealize the output variable of PWM duty ratio, so that the switch can be controlled,andbusbar voltage can be regulated finally. The full bridge inverter circuit is used by the third-endDC/AC. In terms of frequency automatic tracking system design, the FUZZY-DDS controlbased on DSP is proposed, the rough adjustment of frequency is realized by FUZZY control,and then the fine adjustment of frequency by DDS chip AD9833, the precise control offrequency automatic tracking system is realized finally.The design of the whole broadband ultrasonic power is propose, and the realization ofthe main part of the hardware circuit is introduced in detail, including the rectifier module,BUCK voltage regulating module, inverter module, sampling circuit, drive circuit. DSPminimum system is designed, the working principle of the EPWM module is introduced, andthe software flow chart of the system is given.