Electric Arc Furnace Voltage Flicker Mitigation by Applying a Predictive Method with Closed Loop Control of the TCR/FC Compensator

Abstract

Modeling of the three phase electric arc furnace and its voltage flicker mitigation are the purposes of this paper. For modeling of the electric arc furnace, at first, the arc is modeled by using current-voltage characteristic of a real arc. Then, the arc random characteristic has been taken into account by modulating the ac voltage via a band limited white noise. The electric arc furnace compensation with static VAr compensator, Thyristor Controlled Reactor combined with a Fixed Capacitor bank (TCR/FC), is discussed for closed loop control of the compensator. Instantaneous flicker sensation curves, before and after accomplishing compensation, are measured based on IEC standard. A new method for controlling TCR/FC compensator is proposed. This method is based on applying a predictive approach with closed loop control of the TCR/FC. In this method, by using the previous samples of the load reactive power, the future values of the load reactive power are predicted in order to consider the time delay in the compensator control. Also, in closed loop control, two different approaches are considered. The former is based on voltage regulation at the point of common coupling (PCC) and the later is based on enhancement of power factor at PCC. Finally, in order to show the effectiveness of the proposed methodology, the simulation results are provided.

Analysis of power quality in presence of frequency distortions

“…Taking inversely proportional values, we get frequency characteristics, that is, the corresponding 666.67...100 Hz. You can get more accurate frequency values by calculating each column of histogram [11][12][13][14].…”

Ensuring efficient operation of electromechanical systems with frequency regulation with periodic voltage sags

“…But, at time t = 1.2 s. input keys of STATCOM are blocked, which affects voltage level, which exceeds three-fold value of normal voltage on busbar at a short time (due to transient response). Because there was a shutdown of converter blocks, accordingly, there are appears negative disturbing factors affecting performance of electrical installations and overall power supply system [18,20].…”

Modeling of Voltage Fluctuations Generated by Arc Furnaces

“…The issues of voltage fluctuations in power systems and their mathematical description are presented, among others, in the following publications [1][2][3][4][5][6][7]. The voltage fluctuations generated mainly by arc furnaces have been published in [8][9][10][11][12][13][14][15][16]. The significant contribution of the UIE (International Union for Electricity) to the research on voltage fluctuations as a source of the flicker phenomenon should also be emphasized.…”