Research Of Soft Switching Inverter Welding Machine Based On DSP

With the emergence of special purpose DSP for the controller and the development of control theory, the control technique for the inverter power is developing towards digitization, intelligentation and network. At the same time, soft switching technology is becoming the trend of development, because, for hard switching, its switch loss, the peak value of inductive breakaway voltage and the peak value of capacitive switch-on current is large. On this background, the design and development of soft switching inverter welding machine based on DSP is realized.In this system, the DSP typed TMS320LF2407 (produced by TI Company) is applied. Its high speed and precision provides the conditions for the digitization of the control system.The overall design of soft switching inverter welding machine based on DSP is constructed with main circuit and control system, and then, the design of periphery circuit, including the design of signal feedback and isolation, the interface design about analog — to—digital conversion, the design of drive circuit and protecting circuit, etc, which is illuminated later.The main emphasis is the software design. Structured programming technology is adopted in control system software, and the all program can be divided into several modules. The master program' s control process, interrupt sub-program, A/D converter sub-program, arithmetic of PID, PWM control and a variety of anti-interference designs about software are introduced respectively.The welding power of this design is feasible, reliable, which is proved through debugging the main circuit, the control system and the whole-unit. The loop circuit controlling of voltage can be realized in welding process, so the welding machine has been improved anti-interference.