Modeling of Power Supply for Welding with Power Factor Correction

In the article, the options for increasing of the energy efficiency of the resonant welding power supply are analysed. A topology with passive power factor correction by an application of the Valley-Fill type input rectifier is considered. The welding power supply is based on a resonant LLC converter with parameters specially adopted to allow it to be used as a welding power supply, where an electric arc acts as a load. The welding arc in steady state operation is modeled as a resistive load. As a result of the simulation, a decrease of total harmonic distortion (THD) of the input current was confirmed by more than 2 times compared with the use of a conventional diode bridge rectifier, while providing the output voltage and current required for the welding process.