A digital control system designed for ore thermal furnaces producing metallurgical silicon

2021 ◽  
pp. 70-76
Author(s):  
S. A. Martynov ◽  
◽  
V. Yu. Bazhin ◽  
P. A. Petrov ◽  
◽  
...  

This paper considers the key control issues related to non-adjustable parameters in the production of metallurgical silicon in ore thermal furnaces. A series of experiments has been conducted to confirm the possibility of introducing the electrode off-position control. Thus, additional control parameters were introduced in the process control system. The electrode positioning algorithm was tested and adjusted to minimize electrode bending and reduce the risk of breakage and to minimize end cracking and spalling during restarting in the current production environment. An integrated 3D model of the thermal field distribution has been developed and built that accounts for the charcoal moisture content, the position of the electrodes and the power emitted as the charge gets hot. Substantiation is given to the application of this adaptive adjustment algorithm to control the changing parameters as determined by the process conditions, such as the moisture content of the charge, the position of the electrode, the power mode of the furnace. The authors propose to expand the existing control system by adding a digital module, i.e. due to the integration of electrode off-position signals and the use of the adaptive adjustment algorithm and avoiding using any additional corrective signals. This research was carried out as part of the Governmental Assignment No. 075-03-2020-127/1 for the year of 2020, Project No. FSRW-2020-0014. Subject: A crossdisciplinary approach to the comprehensive exploitation of natural resources and conservation. Area (a 2020 topic): “Comprehensive processing of minerals and man-made materials and gasification of solid hydrocarbons: A review and concept elaboration”. As greenhouse gases and carbon are produced as a result of electrode destruction, it is proposed to use the method of gasification and dispose of the heat produced.

Author(s):  
Debargha Chakraborty ◽  
Binanda Kishore Mondal ◽  
Souvik Chatterjee ◽  
Sudipta Ghosh

Author(s):  
Qixin Zhu ◽  
Lei Xiong ◽  
Hongli Liu ◽  
Yonghong Zhu ◽  
Guoping Zhang

Background: The conventional method using one-degree-of-freedom (1DOF) controller for Permanent Magnet Synchronous Motor (PMSM) servo system has the trade-off problem between the dynamic performance and the robustness. Methods: In this paper, by using H∞ control theory, a novel robust two-degree-of-freedom (2DOF) controller has been proposed to improve the position control performance of PMSM servo system. Using robust control theory and 2DOF control theory, a H∞ robust position controller has been designed and discussed in detail. Results: The trade-off problem between the dynamic performance and robustness which exists in one-degree-of-freedom (1DOF) control can be dealt with by the application of 2DOF control theory. Then, through H∞ control theory, the design of robust position controller can be translated to H∞ robust standard design problem. Moreover, the control system with robust controller has been proved to be stable. Conclusion: Further simulation results demonstrate that compared with the conventional PID control, the designed control system has better robustness and attenuation to the disturbance of load impact.


Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 747
Author(s):  
Mai The Vu ◽  
Tat-Hien Le ◽  
Ha Le Nhu Ngoc Thanh ◽  
Tuan-Tu Huynh ◽  
Mien Van ◽  
...  

Underwater vehicles (UVs) are subjected to various environmental disturbances due to ocean currents, propulsion systems, and un-modeled disturbances. In practice, it is very challenging to design a control system to maintain UVs stayed at the desired static position permanently under these conditions. Therefore, in this study, a nonlinear dynamics and robust positioning control of the over-actuated autonomous underwater vehicle (AUV) under the effects of ocean current and model uncertainties are presented. First, a motion equation of the over-actuated AUV under the effects of ocean current disturbances is established, and a trajectory generation of the over-actuated AUV heading angle is constructed based on the line of sight (LOS) algorithm. Second, a dynamic positioning (DP) control system based on motion control and an allocation control is proposed. For this, motion control of the over-actuated AUV based on the dynamic sliding mode control (DSMC) theory is adopted to improve the system robustness under the effects of the ocean current and model uncertainties. In addition, the stability of the system is proved based on Lyapunov criteria. Then, using the generalized forces generated from the motion control module, two different methods for optimal allocation control module: the least square (LS) method and quadratic programming (QP) method are developed to distribute a proper thrust to each thruster of the over-actuated AUV. Simulation studies are conducted to examine the effectiveness and robustness of the proposed DP controller. The results show that the proposed DP controller using the QP algorithm provides higher stability with smaller steady-state error and stronger robustness.


1995 ◽  
Vol 389 ◽  
Author(s):  
K. C. Saraswat ◽  
Y. Chen ◽  
L. Degertekin ◽  
B. T. Khuri-Yakub

ABSTRACTA highly flexible Rapid Thermal Multiprocessing (RTM) reactor is described. This flexibility is the result of several new innovations: a lamp system, an acoustic thermometer and a real-time control system. The new lamp has been optimally designed through the use of a “virtual reactor” methodology to obtain the best possible wafer temperature uniformity. It consists of multiple concentric rings composed of light bulbs with horizontal filaments. Each ring is independently and dynamically controlled providing better control over the spatial and temporal optical flux profile resulting in excellent temperature uniformity over a wide range of process conditions. An acoustic thermometer non-invasively allows complete wafer temperature tomography under all process conditions - a critically important measurement never obtained before. For real-time equipment and process control a model based multivariable control system has been developed. Extensive integration of computers and related technology for specification, communication, execution, monitoring, control, and diagnosis demonstrates the programmability of the RTM.


2013 ◽  
Vol 303-306 ◽  
pp. 1657-1660
Author(s):  
Zhi Guang Zhang ◽  
Wei Hu ◽  
Xiao Qiong Li ◽  
Xue Fei Lv ◽  
Min Ping Zhang ◽  
...  

For the precision rotor position control of stream selector, a control system based on direct current motor (DC motor) has been constructed. The DC motor, with a high-precision incremental encoder used as the driving force, was assembled with the stream selector rotor through a shaft coupling. Following the motor rotation, the encoder generated two-channel quadrature pulses and one channel index pulses. An ultralow-power consumption microcontroller (msp430f2232) received theses pulses and calculated them. The position of the slot was determined by the number of pulses counted from the index pulse. Operator can set and monitored the slot positions of five stream selectors simultaneously through the program which was written with LabVIEW on the host computer. This module featured high reliability and low power consumption compared with the one driven by step motor. Beyond that, it was much smaller and lighter.


Author(s):  
Branislav Ftorek ◽  
Milan Saga ◽  
Pavol Orsansky ◽  
Jan Vittek ◽  
Peter Butko

Purpose The main purpose of this paper is to evaluate the two energy saving position control strategies for AC drives valid for a wide range of boundary conditions including an analysis of their energy expenses. Design/methodology/approach For energy demands analysis, the optimal energy control based on mechanical and electrical losses minimization is compared with the near-optimal one based on symmetrical trapezoidal speed profile. Both control strategies respect prescribed maneuver time and define acceleration profile for preplanned rest-to-rest maneuver. Findings Presented simulations confirm lower total energy expenditures of energy optimal control if compared with near-optimal one, but the differences are only small due to the fact that two energy saving strategies are compared. Research limitations/implications Developed overall control system consisting of energy saving profile generator, pre-compensator and position control system respecting principles of field-oriented control is capable to track precomputed state variables precisely. Practical implications Energy demands of both control strategies are verified and compared to simulations and preliminary experiments. The possibilities of energy savings were confirmed for both control strategies. Originality/value Experimental verification of designed control structure is sufficiently promising and confirmed assumed energy savings.


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