A New Stochastic Model of Electric Arc Furnace Based on Hidden Markov Model: A Study of Its Effects on the Power System

Abstract

Electric arc furnaces (EAFs) are nonlinear and timevariant loads that cause severe fluctuations of current, voltage, and current harmonics, voltage flicker, frequency changes, etc. The requirement is to present an accurate model to analyze the function of these types of loads. In this paper, a new model based on hidden Markov model theory is presented for an electric arc. For this purpose, the characteristic of the arc voltage-current is divided into four regions. Then, on the basis of actual measured samples of an electric arc in several functioning cycles of EAF, different operating points are generated in the form of statistical probability, corresponding to hidden Markov theory in the aforementioned four regions. The arc model is designed in the form of a current-dependent voltage source. Therefore, the proposed model is without linear approximation and corresponds to the actual state. Also, in order to be accurate in flicker modeling, a voltage is randomly considered for the arc model. After designing the aforementioned model, the effects resulting from this electric load in the power system are studied and analyzed. The simulation results are compared with the measured arc to show the accuracy and soundness of the model. Index Terms-Electric arc furnace (EAF), flicker, hidden Markov model (HMM), power quality (PQ).

A New Dynamic Intelligent Time Domain Arc Furnace Modeling based on Combination Adaptive Neuro-fuzzy Inference System and Chain Code

“…It should be noted that Figures 11(a2), 11(b2), and 11(c2) are plotted in one EAF complete process. Equation (14) is considered by extracting the effects of furnace parameters, such as flexible cables, electrodes, etc., as shown in Figure 7.…”

“…The coefficient changes for EAF modeling based on V-I characteristic are presented in [10,12,13]. In [14], an arc model based on the hidden Markov model (HMM) is presented. Single-phase HMM, a necessity for flicker function, but lacking EAF parameter calculations, mismatches the measured and simulated voltage waveform in the main bus.…”

Electric arc furnace power quality improvement by applying a new digital and predicted-based TSC control

“…Up to now, different models for EAFs have been suggested [1][2][3][4]. In this paper, with regard to the disadvantages of those models, the arc model was based on the statistical-probabilistic method employing the hidden Markov model (HMM) [5]. This model is based on system identification by considering a specific EAF so that the arc model is determined through sampling the arc current in the initial melting (scrap), mild melting, and refinement stages.…”

“…Due to economic problems, customary SVCs are applied to compensate different PQ parameters such as reactive power and power factor [5][6][7][8][9].…”

“…The EAF model was based on the hidden Markov model (HMM) proposed in [5]. Therefore, the designed power system had a minimum error for the KHSC.…”