Development of Enhanced Electric Arc Furnace Models for Transient Analysis

Electric arc furnaces (EAFs) are a main cause of voltage flicker due to the interaction of the high demand currents of the loads with the supply system impedance. In order to adequately understand and analyze the effects on the power system from these loads, obtaining an accurate representation of the characteristics of the loads is crucial. In this paper, a mixed chaotic EAF model to represent the low-frequency and high-frequency variations of the arc current, respectively, and a chain-shaped chaotic EAF model to characterize the current variation have been proposed. The concept of chaotic parameters, such as chaotic resistance, inductance or admittance, also has been proposed for the characterization of arc furnace operation and the highly nonlinear physical processes. In addition, a DLL–Dynamic Link Library–module, which is a FORTRAN interface with TACS–Transient Analysis of Control Systems–is developed to implement the chaotic load models in the EMTP–Electromagnetic Transients Program. The simulation results are presented in comparison with the actual data to illustrate the validity of the models.