scholarly journals Analysis of the influence of the parameters of the power supply network on the operating modes of the electric drives of the stands of the hot rolling mill 1700 of ArcelorMittal Temirtau JSC

Author(s):  
I V Breido ◽  
V M Druzhinin
Vestnik IGEU ◽  
2021 ◽  
pp. 41-50
Author(s):  
A.A. Nikolaev ◽  
I.G. Gilemov ◽  
M.V. Bulanov

Advanced rolling mill electric drives are based on frequency converters (FC) with active rectifiers (AR). Operation of such converters has negative impact on the in-plant power supply system. To improve the voltage quality of active rectifiers, special algorithms of pulse-width modulation algorithms are used. As a rule, the study of the effect of electric drives with FC-AR on the supply network are carried out based on simplified mathematical models that do not consider possible resonance phenomena in the power supply system and operating mode of electric drives. Thus, the aim of the paper is to assess the acceptability of such an approach. The trends of the main parameters of the rolling mill electric drives have been recorded during the rolling cycle using the IBA PDA software. The obtained dependencies values have been approximated and applied in a complex simulation model of the in-plant power supply system. It considers the parameters of the supply network, cable lines, step-down transformers, rolling mill electric drives and other electrical receivers of the shop substations. The main assumption in simulation modeling is to consider the loads of other electrical receivers in the form of constant values. The authors have studied the effect of the operating modes of the rolling mill electric drive on the electric power quality in the 10 kV distribution network of the in-plant power supply system of a metallurgical enterprise. It is found that the total harmonic distortion KU at 10 kV sections of the main step-down substation of a metallurgical enterprise is changing in a nonlinear manner in the dynamic modes of acceleration and deceleration of electric drives. The nature of the coefficient KU also depends on the presence of resonance phenomena in the frequency response of the medium voltage supply network. The obtained results prove the need to consider the operating modes of electric drives when studying the influence of electric drives with FC-AR on the quality of the supply network voltage. in case we conduct experimental research using the equipment of the enterprises, as well as during theoretical research using mathematical models. The adequacy of the simulation model has previously been confirmed by experimental data and previous studies.


2015 ◽  
Vol 792 ◽  
pp. 15-20 ◽  
Author(s):  
Aleksey S. Evdokimov ◽  
Vadim Rifhatovich Khramshin ◽  
Sergey A. Evdokimov

It has been proven that the introduction of the systems for continuous control of the equipment technical state is a necessary requirement of the modern maintenance of the critical equipment. The paper proposes the list of the processing facilities applied within the development systems for technical state control. The task of development of the system for recording, storing and displaying oscillographs of the automated electric drives of the wide-strip hot-rolling mill has been defined. The paper offers the analysis of the recording system based on the remote I/O controllers and the system with distributed industrial computers. The most informative-significant signals are listed. The network topology of the decentralized system implemented at the 2,500 mm wide-strip hot-rolling mill of OJSC Magnitogorsk Iron and Steel Works is suggested. Oscillographs of the main coordinates of the mill's electric drives obtained by means of the introduced system are provided.


Author(s):  
E. N. Shiryaeva ◽  
M. A. Polyakov ◽  
D. V. Terent'ev

Complexity of modern metallurgical plants, presence of great number of horizontal and vertical interactions between their various structural subdivisions makes it necessary to apply a systems analysis to elaborate effective measures for stable development of a plant operation. Among such measures, digitalization of a plant is widespread at present. To implement the digitalization it is necessary to have clear vision about links at all the levels of the technological system of a plant. A terminology quoted, accepted in the existing regulatory documents for defining of conceptions, comprising the technological system. It was shown, that the following four hierarchical levels of technological systems are distinguished: technological systems of operations, technological systems of processes, technological systems of production subdivisions and technological systems of plants. A hierarchical scheme of technological systems of hot-rolled sheet production at an integrated steel plant presented. Existing horizontal and vertical links between the basic plant’s shops shown. Peculiarities of flows of material, energy and information at the operation “rolling” of the technological system “hot rolling of a steel sheet” considered. As a technical system of the technological process of the hot rolling, the hot rolling mill was chosen. A structural diagram of the hot rolling mill was elaborated, the mill being consisted of reheating furnaces, roughing and finishing stand groups, with an intermediate roll-table between them, and down-coilers section. Since the rolling stands are the basic structural elements of the hot rolling mill, structural diagrams of a roughing and a finishing stands were elaborated. Results of the systems analysis of the technological and technical systems, hierarchically linked in the process of steel sheet hot rolling, can be applied for perfection of organization structure of the whole plant, as well as for elaboration mathematical models of a system separate elements functioning, which is a necessary condition for a plant digitalization.


Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 869
Author(s):  
Rongrong Peng ◽  
Xingzhong Zhang ◽  
Peiming Shi

Based on the analysis of the influence of roll vibration on the elastoplastic deformation state of a workpiece in a rolling process, a dynamic rolling force model with the hysteresis effect is established. Taking the rolling parameters of a 1780 mm hot rolling mill as an example, we analyzed the hysteresis between the dynamic rolling force and the roll vibration displacement by varying the rolling speed, roll radius, entry thickness, front tension, back tension, and strip width. Under the effect of the dynamic rolling force and considering the nonlinear effect between the backup and work rolls as well as the structural constraints on the rolling mill, a hysteretic nonlinear vertical vibration model of a four-high hot rolling mill was established. The amplitude-frequency equations corresponding to 1/2 subharmonic resonance and 1:1 internal resonance of the rolling mill rolls were obtained using a multi-scale approximation method. The amplitude-frequency characteristics of the rolling mill vibration system with different parameters were studied through a numerical simulation. The parametric stiffness and nonlinear stiffness corresponding to the dynamic rolling force were found to have a significant influence on the amplitude of the subharmonic resonance system, the bending degree of the vibration curve, and the size of the resonance region. Moreover, with the change in the parametric stiffness, the internal resonance exhibited an evident jump phenomenon. Finally, the chaotic characteristics of the rolling mill vibration system were studied, and the dynamic behavior of the vibration system was analyzed and verified using a bifurcation diagram, maximum Lyapunov exponent, phase trajectory, and Poincare section. Our research provides a theoretical reference for eliminating and suppressing the chatter in rolling mills subjected to an elastoplastic hysteresis deformation.


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