Development of an arc furnace model for power quality studies

Arc furnaces are known to cause voltage flicker and to inject harmonics into the power system. Utilities and customers are concerned about these effects and try to take precautions to minimize them. Simulation is a powerful means of testing and verifying proposed solutions to this end. Developing an arc furnace model that can duplicate its erratic operation has been a challenging task for several researchers in the past. Two classes of approaches have been proposed for the modeling problem: stochastic and chaotic. Both methods have their advantages and shortfalls as shown in related publications. In this paper, the authors present the results of a study, where an arc furnace is modeled using both chaotic and deterministic elements. The flicker effect, which is the manifestation of voltage fluctuations, is captured using the well studied Chua's chaotic circuit, whereas a dynamic model in the form of a differential equation is used for the electric arc. The resulting model produces both effects and the resulting harmonic spectrum of the simulated arc furnace voltage is used as an illustration.