Finite Element-based Simulation of low-frequency AC Arc Furnace and Extraction of Arc Physical characteristics to investigate the stability of electric arcs with dynamic behavior

Electric arc furnaces are the largest concentrated, nonlinear and chaotic loads in power distribution networks. Magnetic modeling and simulation of such loads have the least error with respect to the physical nature of the arc and play a significant role in the accuracy of the studies. In this paper, the electromagnetic simulation of a low-frequency AC arc furnace is performed based on finite element method, utilizing the powerful COMSOL Multiphysics software. The finite element method for magnetic, thermal and dynamic analysis is a commonly used method and its capability in various physical fields has been repeatedly proven. In this finite element simulation, the corresponding electrical circuit, the electrode physical dimensions, the initial thermal condition and the furnace power supply system are also considered. By simultaneous solving of different physical equations in COMSOL Multiphysics software and applying the magnetohydrodynamic principles, Ampere's law, Ohm's law, and Maxwell’s equations, the arc model and plasma generation are investigated. Then, by extracting the results and comparing them with previous studies, the stability of the arc is evaluated. A stable arc decreases the harmonic components and also diminishes the voltage flicker severity imposed on the grid and thus, reduces the need for compensator equipment.