Design Of High Power Ultrasonic Control System Based On BUCK Circuit

Ultrasonic driving technology is to convert the mains power into ultrasonic frequency power signal,ultrasonic power signal through the transducer to produce ultrasonic vibration of the physical vibration.Ultrasound technology is widely used,with ultrasound cutting,ultrasonic extraction,ultrasonic welding and other branches.Ultrasonic plastic welding have incomparable advantages compared to other traditional welding methods,the ultrasonic drive technology be concerned by more and more schools and research institutions at home and abroad.Ultrasonic driving determines the performance of the entire ultrasonic welding system.At present,there are still some problems in the application of the ultrasonic plastic welding power technology.For example,there will be low efficiency and poor welding quality problems in the application of low-power ultrasonic plastic welding.In practice,the transducer resonant frequency and output power will continue to change due to the parameters change of the system itself and the working environment.So the output power should be ensured relatively stable,so as to ensure the work effect of ultrasonic power.The output power of ultrasonic power needs to be adjustable and controllable to adapt to different materials and different precision of ultrasonic welding needs.In this dissertation,the BUCK circuit is used to achieve that the power output can adjusted linearly in a wide range;the bridge inverter circuit converts the DC power supply into ultrasonic square wave power supply,and it also acts as the hardware basis for the frequency lock and frequency tracking;the series matching circuit is used to match the transducer to obtain the best output performance.So the output power and transmission efficiency of the ultrasonic welding system be improved and the power regulation performance of the ultrasonic power supply be optimized.A simulation circuit of the high power ultrasonic power supply is built under the Multisim simulation platform.The design of the whole circuit and the function of each module are verified by the platform.The traditional PID algorithm,the traditional sliding mode variable structure algorithm and the Super-Twisting algorithm are compared with the traditional BUCK circuit.And the Super-Twisting algorithm been select owing to the advantage of strong robustness based on the simulation analysis in Matlab-Simulink platform.Finally,the experimental platform of ultrasonic power supply which can reach 2k W output power is implemented.The experimental results show that the ultrasonic power driver based on BUCK DC chopper can realize the stable and efficient driving of the transducer.The BUCK circuit is using to adjust the output power of the power supply,and the Phase-shifted full-bridge circuit is using to adjust the driving signal of the ideal frequency.So the power adjustment capability of the circuit is optimized and the 2 kW output targets be achieved.