Design and implementation of a 400A industrial welding machine

Inverter based welding machines are getting popular and favored by users due to their size, fast response and high efficiency properties. In inverter welding machines, grid signal is rectified, and the line voltage is switched at high frequencies and the power is transferred to the secondary side of a high frequency transformer. There is again rectifier circuit in secondary side. After rectification, a filter inductor is used for current regulation. The filtered voltage is applied between welding electrode and work piece. The duty cycle of the semiconductor switches in primary side adjusts the weld current. In this thesis, 17.2 kW welding machine is designed and implemented. The designed machine is a part of project of generate new generation of welding machine in cooperation with Linkas Teknoloji AŞ. A full-bridge topology is used, and smart control tool of simulation program is used to design the controller for welding machine. Then the controller was modelled and tested. The results of simulation were used to program the digital signal processor unit in real circuit. Finally, experimental results are presented. Experimental results are in good agreement with simulation results. Keywords: Arc welding machine, pulse width modulation, voltage source inverter, full bridge inverter, constant current, constant voltage.