Power factor correction and DC voltage control limits for arc welding application using pulsed current

This paper deals with Power Factor Corrector (PFC) based AC/DC-DC/DC energy conversion structure for arc welding application, under specific pulsed load. Power conversion chain includes a PFC Boost converter connected to the grid providing a high continuous voltage which is then used as voltage supply by a DC/DC isolated Full-Bridge Phase-Shift Zero-Voltage-Switching (FB-PS-ZVS) converter. The description of this structure implies two current and one voltage regulations obtained by using a Phase-Shift Self-Oscillating Current Controller (PSSOCC) for grid current control and PI controls for others. PFC regulation is presented in this work. The regulation of the current load uses a PI and depends on the welding process. Matlab/Simulink simulations present results for continuous and pulsed current with load variations. These results lead to the fact that a compromise is unavoidable between having a unity power factor or having a high welding arc quality, through a well PFC Boost voltage regulation, when load's variations are non-negligible.