Three-phase, self-commutated, current source converter controller for plasma torches applications

Nowadays there is an increasingly use of plasma torches in processes that requires high temperatures, such as metal recovering and residues treatment. Special care must be taken to the problems related to power quality and process efficiency. Commercially available power supplies for torches fail to satisfy the above conditions. After a brief introduction on the plasma torches, this paper focuses on presenting a three-phase, self-commutated, current source converter. This paper concentrated on proposing a simple and good performance controller strategy, presenting its design procedure. The controller achieves fast DC current regulation, high power factor at the AC side and a compensator for AC side oscillation damping. Performance is validated by numeric simulation.