Study And Application Of Semi-bridge Type 250A Inverter CO₂ Arc Welding Main Power Source

CO₂ gas shield arc welding is used more and more widely because of its some advantages such as higher efficiency,lower energy consumption,lower cost and so on. However,it is until now that the problems like large spatter and bad formation of welding bead have not been solved successfully. Which restricts the CO₂ gas shield arc welding from being popularized and applied. For another thing,although inverter welding power source has also been widely used owing to its excellent technological characteristics such as higher efficiency,smaller bulk and lighter weight,we know that there is still a long way for our country to keep pace with advanced countries in term of this technology. The difference mainly manifests the equipment, that is, the lower controllable performance and lower dependability of the equipment. In technology, the difference reflects the lower stability of droplet transfer, bigger welding metal spatter and worse shape of welding seam. Therefore,it is very realistic for us to study IGBT type inverter co2 arc welding power source. The paper firstly introduces the history and development of the arc welding inverter power source. At the same time,the paper forecasts the foreground and trend of the power source. That is to face to higher efficiency,larger bulk,higher frequency,lighter,modularization and to reduce the power wasting of IGBTs. Its core consist in improving the dependability of the system. This researching task is put forward on the base of analyzing the application of the welding power source in Chongqing and Chengdu. The structure and component of the IGBT inverter type welding power source are introduced in the paper. The welding power source include main circuit,control circuit and protect circuit. In main circuit,we compare the circuit form with each other and choose semi-bridge type inverter main circuit at last. The paper introduce many characteristics of IGBT in detailed. At the same time,each parameter of those components in input–rectifier-filter circuit,output-rectifier-filter circuit,IGBT inverter circuit,intermediate frequency transformer etc. are designed and selected elaborately. Control circuit is based on the PWM technology of the SG3526 chip. On the basis of the need of CO₂ welding for Out-characteristics of power source and the need of main circuit for driving circuit, Simultaneity driving circuit and Out-characteristic control circuit are designed in detail in the paper. In protect circuit,the paper bring forward to many protective measures such as over-current,over-voltage. The experiment of the waveform of the main circuit is made in the paper. The experiment indicate that the design of the main circuit is reasonable,the parts of the welding power source run reliably,the output-waveform is appropriate,and the anticipate purpose of the paper is obtained.