The use of a unified power flow controller (UPFC) to improve the power transfer in an EAF is investigated. The implemented equipment used techniques of hardware-in-the-loop to determine the required specific characteristics of the UPFC to improve the stability of the arc. The arc is mainly responsible for the conversion of electromagnetic power into thermal power and heat transfer. The stability studies of power networks help in improving the stability of the arc. These are the topics covered in this paper. This research also shows how it is possible to achieve an increment of the stability of the arc with the enhancement of the power quality between the main transformer and the distribution system through the decrease of the THDI, unbalance, and flicker.