IGBT Inverter Power System Based On DSP Control In CO₂ Arc Welding

CO2 Arc Welding is a kind of advanced welding method. This paper introduces inverter technology and uses IGBT as power component to research high performance and high efficiency CO2 arc welding power source. The control circuit is based on PWM technique and uses negative-feedback by voltage to acquire strong static feature of CO2 welder and uses closed-loop of negative-feedback by current to control the waveform of short circuit. The idea of controlling the current waveform by means of switching the current closed-loop or the voltage closed-loop in different circuit state is brought out.First of all, this paper presents constitute of the arc welding power and illustrates functions of each sections. Compared with general arc welding power, inverter arc welding has a series of advantages, such as save material, space and weight, high efficiency, high dynamic respond etc. Then it explains the main circuit's structure and the key circuit's design formulas.This paper selects Texas Instruments' TMS320LF2407A DSP as the controller which is suit for industry control. Then it explains the performance and characteristic of this DSP. We design the control system which is based on TMS320LF2407A DSP. Introduce the design of DSP control board, including: A/D,D/A convert circuit design, external RAM/ROM system design, RS-232 serial communication interface design, 3.3V-5V voltage convert circuit design and JTAG emulator interface design etc. Emphasizes on detail designs, for instance, protection of electric components, address decode, communication formation etc. Then the paper illustrates the design of IGBT driver circuit and the welding feeder control circuit. Discussing the DSP board's anti-interference method in the strong electromagnetic interference environment. Designing the PCB of the DSP system based on several effective anti-interference methods.This paper analyzes the diagram of welding control system and builds its math model after presenting the feature of CO2 arc welding. Then, we simulate the model in MATLAB in order to verify the system's feasibility. Finally, in this paper, we explain the development environment and program language of the TMS320LF2407A DSP, and design the program of CO2 arc welding control.