Research On The Control Of High Power And High Frequency Ultrasonic Biological Treatment System

With the continuous development of biological treatment technologies, the high demandfor its efficiency is increasing. Ultrasound technology is applied to biological treatment toimprove the efficiency. Therefore, it is particularly important to research on the ultrasonicpower system to improve its work efficiency and intelligence.This paper focuses on the research of ultrasonic power frequency tracking and powerregulation. This paper proposes a composed control strategy which combines a fuzzycontroller with digital phase locked loop in terms of frequency automatic tracking. When theerror value of frequency is large, fuzzy controller is adjusted to decrease the error value, thenDPLL is used to regulate for achieving automatic tracking. And in terms of power regulation,the voltage and current double closed-loop control strategy is used for buck converter, andintegral separation PID algorithm with dead zone is used to adjust the PWM duty cycle.It usesMatlab/Simulink development environment and fuzzy logic toolbox to model and simulate forfrequency tracking method and power adjustment method The simulation results are analyzedand verified.In this paper,30kHz/2kw of the ultrasonic power is as the design object. It comparesvarious parts of the program and selects the reasonable system design. It mainly uses thetheory of sinusoidal pulse width modulation. This paper designs and selects the specificparameters of power device in the main circuit, including the rectifier bridge, buck conveter,inverter, high-frequency transformers, the matching inductance, drive circuit etc. The controlcircuit is based on TMS320F2812as the core, including power circuit, clock circuit, interfacecircuit, etc. The sampling circuit collects voltage and current signal across the transducer bytransformer, and the sampling signal is sent to the DSP to achieve the frequency tracking andpower control. In order to guarantee the power supply working safely and reliably, aprotection circuit is designed such as over-voltage protection, over-current protection andover-temperature protection.Finally the design of the DSP minium system, the main circuit and drive circuit is madeof PCB board. The experimental prototype is built for experimental verification related.Power supply is stable, the output waveform and experimental data is measured, and theresults verify the rationality and reliability of design.