Based On DSP Controlled IGBT Inverter CO₂ Welding Power Source

CO2 arc welding is an advanced method.This paper introduces the principles,characteristics and the development history of CO2 welding, as well as the development of the present situation at homeland and overseas. This article in order to develop an energy-efficient CO2 welding power source,so we have deep research in the inverter main circuit, control circuit, driver circuit and wire drive circuits. I have detail design of the main circuit, including the three-phase full-bridge rectifier circuit, the full-bridge inverter of IGBT, the IF transformer design and the design of IGBT protection circuits and soft-start circuitry. The safeguard circiut mainly consists of over-current, over-heat, over-votage and low-vogate circuits, as long as there is any one occur will be interrupted PWM, in order to achieve protection. The control circuit based on DSP generated two PWM pulses not overlapped each other. And, using closed-loop negative feedback by voltage to acquire strong feature of CO2 welder and using closed-loop of negative feedback by current to control the short-circuit waveform. As the DSP output PWM wave can not directly drive IGBT, at last the pulses are used to spring IGBT must be magnified. This paper specifically describes the M57959 drive circuit. Besides, a wire-giving system is designed in this paper, which takes PWM principle.The reliability and anti-jamming are considered in design the welding machine's main circuit and the control circuit elements. System software using assembly language and designing in a modular way. Paper describes in detail of the main program, interrupt service routine, as well as the function and structure of the subroutines.The DSP simulation environment is necessary for the designing DSP systems, the paper illuminates the DSP development environment CCS2000, and how to use the development tools of ICETEK-5100USB indetail.Through the experiment Corresponding data and waveforms are recorded. Problems occurred in experiment are investigated and put forward solution. The experiment results verify that the inverter power source has rapid response-speed, high reliability, a strong ability of anti-jamming, basically fulfill the original design concept and requirements.Finally, some improved advices are put forward in allusion to problems and deficiency in this welding machine, which make a found ground forfollowing research of the Inverter CO2 Welding power.