Development Of Magnetic Control Welding Pulse Power Supply Based On FPGA

In the field of magnetron welding,the shape of the welding arc,molten pool,and droplet transition can be changed by applying a magnetic field,leading to fine weld grain and improving the lap accuracy,and the surface quality of the cladding layer.However,the induction of high-frequency magnetic fields in the welding zone is still under research and the coupling mechanism between the magnetic field and the welding arc has not yet formed a complete system.The development of a high-frequency pulse power supply with adjustable pulse amplitude,frequency and duty cycle in the field of magnetron welding is of great significance for the study of magnetron welding.The main research of this article is as follows:(1)According to the technical requirements of the pulse power supply for magnetron welding,the overall design of the pulse power supply is proposed.The principle of pulse power supply and its control method is focused,and the structure of the combination of the main circuit of the pulse power supply and the FPGA-based control system are determined.(2)According to the technical indicators of the pulse power supply for magnetron welding,the main circuit of the pulse power supply is studied and designed.The structure of "LLC resonance inverter circuit + chopper circuit" is used for the main circuit of the pulse power.This paper focuses on the research and parameter design of the LLC resonant inverter circuit,and the main circuit of the pulse power supply is simulated and verified in matlab.(3)According to the control requirements of the power supply,the FPGA control board is designed and manufactured.The research is mainly focused on the design of the control system hardware,pulse generator,control system software,drive circuit and so on.Meanwhile,the control system was tested and verified.(4)The pulse power supply is tested to verify the output characteristics and control effect.It is showed that the output voltage of the developed magnetron welding pulse power supply can reach 36 V and the frequency can reach 300 k Hz.The FPGA-based control system can effectively control the amplitude,frequency and duty cycle of the output pulse voltage,and reach the design of the pulse power supply.