A SERIES RESONANT CONVERTER FOR ARC-STRIKING APPLICATIONS

Initiation of a plasma conduction state requires a relatively large vo ltage to ionize the gas. A new version of the series resonant converte r is proposed that uses the magnetizing inductance of the transformer for resonance. This converter is not suitable for most power supply ap plications, but the unique load characteristics associated with plasma loads make this type of converter well suited for are striking, while allowing safe operation during the plasma state. A feature of the res onant converter is that the controller need not be complex, thus makin g it suitable for application in competitive industrial systems. Possi ble transformer configurations are investigated, which include an air core and a number of ferrite-cored transformers, The series resonant c onverter with the best-suited transformer is verified experimentally i n a tungsten inert gas welding application.