A Frequency Domain Approach for Modeling DC Arc Furnaces under Fluctuating Conditions

This paper presents a direct method in the frequency domain for modeling DC arc furnaces (DCAF) under fluctuating conditions. The procedure takes advantage of the switching function approach for obtaining a detailed representation of the DCAF. The model provides very fast calculations of the flicker interharmonic voltages and currents as well as it offers a basis for estimating the fluctuations of the arc from measurements on the AC side. With this procedure, an exhaustive analysis is developed where a deep insight is provided for better understanding the process by which flicker interharmonic components are generated. With this, flicker power flow in terms of Pst values is possible not only for the DCAF installation but also for large systems where the DCAF is connected. The method has been validated with measurements and with time domain simulations.