scholarly journals TECHNICAL AND ECONOMIC ASSESSMENT OF THE RECONSTRUCTION OF THREE-PHASE ELECTRIC-ARC STEEL FURNACE

2021 ◽  
Vol 2021 (1) ◽  
pp. 61-67
Author(s):  
V.I. Hudym ◽  
◽  
V.V. Kosovska ◽  
N.P. Yavorska ◽  
T.I. Danko ◽  
...  

The technological units of electric arc steel remelting are among the most energy-intensive consumers for whom the problem of energy saving is extremely urgent. The proposed reconstruction of the electric-arc steel furnace is aimed at reducing the amount of electricity consumption. The feasibility study makes it possible to assess the technical and economic parameters of project of an electric-arc steel furnace reconstruction. The simulation results of the reconstructed electric furnace showed that due to the optimal placement of electric arcs in the electric furnace space, the duration of the metal melting stage can be reduced by approximately 19 min. Cost-effectiveness calculations for the implementation of the innovative solution showed that reducing the duration of steel remelting in a reconstructed furnace reduces the electricity consumption by approximately 28% per process. The article takes into account only the reduction of electricity consumption, but does not take into account the possibility of improving the productivity of the furnace by increasing the number of technological processes per shift. References 7, figures 3, table 1.

Electricity ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 187-204
Author(s):  
Gian Giuseppe Soma

Nowadays, response to electricity consumption growth is mainly supported by efficiency; therefore, this is the new main goal in the development of electric distribution networks, which must fully comply with the system’s constraints. In recent decades, the issue of independent reactive power services, including the optimal placement of capacitors in the grid due to the restructuring of the electricity industry and the creation of a competitive electricity market, has received attention from related companies. In this context, a genetic algorithm is proposed for optimal planning of capacitor banks. A case study derived from a real network, considering the application of suitable daily profiles for loads and generators, to obtain a better representation of the electrical conditions, is discussed in the present paper. The results confirmed that some placement solutions can be obtained with a good compromise between costs and benefits; the adopted benefits are energy losses and power factor infringements, taking into account the network technical limits. The feasibility and effectiveness of the proposed algorithm for optimal placement and sizing of capacitor banks in distribution systems, with the definition of a suitable control pattern, have been proved.


Author(s):  
Arash Kiyoumarsi ◽  
Abolfazl Nazari ◽  
Mohammad Ataei ◽  
Hamid Khademhosseini Beheshti ◽  
Rahmat‐Allah Hooshmand

PurposeThe purpose of this paper is to present a 3D finite element model of the electromagnetic fields in an AC three‐phase electric arc furnace (EAF). The model includes the electrodes, arcs, and molten bath.Design/methodology/approachThe electromagnetic field in terms of time in AC arc is also modeled, utilizing a 3D finite element method (3D FEM). The arc is supposed to be an electro‐thermal unit with electrical power as input and thermal power as output. The average Joule power, calculated during the transient electromagnetic analysis of the AC arc furnace, can be used as a thermal source for the thermal analysis of the inner part of furnace. Then, by attention to different mechanisms of heat transfer in the furnace (convection and radiation from arc to bath, radiation from arc to the inner part of furnace and radiation from the bath to the sidewall and roof panel of the furnace), the temperature distribution in different parts of the furnace is calculated. The thermal model consists of the roof and sidewall panels, electrodes, bath, refractory, and arc. The thermal problem is solved in the steady state for the furnace without slag and with different depths of slag.FindingsCurrent density, voltage and magnetic field intensity in the arcs, molten bath and electrodes are predicted as a result of applying the three‐phase AC voltages to the EAF. The temperature distribution in different parts of the furnace is also evaluated as a result of the electromagnetic field analysis.Research limitations/implicationsThis paper considers an ideal condition for the AC arc. Non‐linearity of the arc during the melting, which leads to power quality disturbances, is not considered. In most prior researches on the electrical arc furnace, a non‐linear circuit model is usually used for calculation of power quality phenomena distributions. In this paper, the FEM is used instead of non‐linear circuits, and calculated voltage and current densities in the linear arc model. The FEM results directly depend on the physical properties considered for the arc.Originality/valueSteady‐state arc shapes, based on the Bowman model, are used to calculate and evaluate the geometry of the arc in a real and practical three‐phase AC arc furnace. A new approach to modeling AC arcs is developed, assuming that the instantaneous geometry of the AC arc at any time is constant and is similar to the geometry of a DC arc with the root mean square value of the current waveform of the AC arc. A time‐stepping 3D FEM is utilized to calculate the electromagnetic field in the AC arc as a function of time.


2021 ◽  
Vol 17 (1) ◽  
pp. 1-13
Author(s):  
Adala Abdali ◽  
Ali Abdulabbas ◽  
Habeeb Nekad

The multilevel inverter is attracting the specialist in medium and high voltage applications, among its types, the cascade H bridge Multi-Level Inverter (MLI), commonly used for high power and high voltage applications. The main advantage of the conventional cascade (MLI) is generated a large number of output voltage levels but it demands a large number of components that produce complexity in the control circuit, and high cost. Along these lines, this paper presents a brief about the non-conventional cascade multilevel topologies that can produce a high number of output voltage levels with the least components. The non-conventional cascade (MLI) in this paper was built to reduce the number of switches, simplify the circuit configuration, uncomplicated control, and minimize the system cost. Besides, it reduces THD and increases efficiency. Two topologies of non-conventional cascade MLI three phase, the Nine level and Seventeen level are presented. The PWM technique is used to control the switches. The simulation results show a better performance for both topologies. THD, the power loss and the efficiency of the two topologies are calculated and drawn to the different values of the Modulation index (ma).


Author(s):  
Liu Yang ◽  
Qinyue Tan ◽  
Di Xiong ◽  
Zhengguang Liu

The overrun of transient power quality index caused by the large-capacity electric arc furnace (EAF) has become a prominent problem affecting the safe and stable operation of the power system. (1) In this paper, the relationship between arc furnace volt-age and current is derived based on the different stages of arc combustion, and the random variation of chaotic phenomenon of the arc voltage are simulated. Established an EAF model suitable for the study of transient power quality problems. (2) Take 50t AC EAF as an example to analyze the reactive power impact and the influence on the point of common coupling (PCC) voltage caused by the three-phase short circuit of the electrode. The results show that the experimental results are consistent with the theoretical analysis, verifying the correctness and effectiveness of the model. (3) When the three-phase short-circuit occurs, the reactive power impact is nearly 6 times that of normal operation, the short-circuit current is 2.66 times that of normal operation, and the effective value of the PCC voltage has dropped by 40.37%, which provides a theoretical basis for real-time compensation of impulsive reactive power and improvement of the transient power quality of the EAF.


2014 ◽  
Vol 532 ◽  
pp. 62-69
Author(s):  
Yi Chuan Gao ◽  
Guo Chang Liu

A novel actuator controller for greenhouse control system is proposed in this paper. This controller can solve the problems existing in traditional greenhouse control system such as generating electric arc, short circuit risk, lack of communication and smart ability. We adopt five separate magnetic latching relays to control the three-phase motor. In order to prevent generating electric arc in the process of turning off relay, the alternating current zero-crossing detection circuit is designed. In software side, the relay-off task program is running in the real-time operating system, which can ensure turn-off operation at the point of alternating current zero-crossing. In addition, the controller is capable of detecting motors operation parameter and having multiple communication interfaces. Finally, we implement our controller in practice and experimental results meet the design requirements.


Author(s):  
M. Gaiceanu ◽  
S. Epure ◽  
C. R. Dache ◽  
S. Ciuta

Abstract The research purpose of the authors is reducing the energy consumption of the main worldwide consumer - the electric motors- by useful utilization of the input energy through the Regenerative Electric Drive System having also the power quality features. The prototype of the electric elevator consists mainly of two trolley: one serve for the active load, and the other as counterweight, gearbox, power converter, induction machine and chain transmission. The elevator is driven by using 4kW three-phase induction machine through AC-AC power converter and has the capacity of 450 kg. The numerical simulation results and the experimental platform are shown.


2019 ◽  
Vol 63 (3) ◽  
pp. 169-177
Author(s):  
Mohamed Amine Khelif ◽  
Azeddine Bendiabdellah ◽  
Bilal Djamal Eddine Cherif

Currently, with the power electronics evolution, a major research axis is oriented towards the diagnosis of converters supplying induction machines. Indeed, a converter such as the inverter is susceptible to have structural failures such as faulty leg and/or open-circuit IGBT faults. In this paper, the detection of the faulty leg and the localization of the open-circuit switch of an inverter are investigated. The fault detection technique used in this work is based essentially upon the monitoring of the root mean square (RMS) value and the calculation of the mean value of the three-phase currents. In the first part of the paper work, the faulty leg is detected by monitoring the RMS value of the three-phase currents and comparing them to the nominal value of the phase current. The second part, the open-circuit IGBT fault is localized simply by knowing the polarity of the calculated mean value current of the faulty phase. The work is first accomplished using simulation work and then the obtained simulation results are validated by experimental work conducted in our LDEE laboratory to illustrate the effectiveness, simplicity and rapidity of the proposed technique.


2013 ◽  
Vol 385-386 ◽  
pp. 1216-1219
Author(s):  
Yun Liang Wang ◽  
Yong Le Zhao

This paper presents fixed switching frequency direct power control (FSF-DPC) for three-phase AC/DC converter. Sensorless control strategies based on virtual-flux can optimize the performance of the system. In this paper, realization of pulse width modulation method for FSF-DPC is presented. The simulation results show that the system running performance is good.


Sign in / Sign up

Export Citation Format

Share Document