Automated Process Control System Research Articles

Technology of Intellectualization of Automated Process Control Systems Based on a Software and Hardware Complex

Technology of Intellectualization of Automated Process Control Systems Based on a Software and Hardware Complex

Преимущества интеграции автоматизированных систем управления технологическим процессом угольных шахт с системами определения местоположения

Coal mining companies, especially those involved in underground operations, are currently at different stages on their way to digitalization and face a number of challenges, which are described in the article. One group of such problems is the difficulties concerned with the coal mine dispatching control. The paper shows how a properly selected approach, i.e. the integration of various automated process control systems with positioning systems, provides a solution to these problems and offers significant advantages both regarding the industrial safety and maximizing the economic effect. Examples of such integration are given for the conveyor transport control system, for the air and mine gas control systems as well as a CCTV systems with positioning systems within the Smart Mine® complex. An assessment of the current technical basis for the implementation of this approach is given, and the advantages of using a single platform for subsystems of the multi-functional safety system and production management systems are shown.

Analysis of the State of Moisture Control to Ensure and Regulate the Quality of Grain and Grain Products

The article discusses the methods for determining the maturity of grain and describes its behavior during harvesting, to optimize the selection of the grain moisture state, discusses the requirements for the choice of measurement method and the design of moisture control measuring devices, as well as its high accuracy and the possibility of measuring from field conditions, collection, storage, transportation, and industrial processing and release of finished products of granular materials. The purpose of the study is to improve the efficiency of control and management of complex technological processes and moisture control devices for granular bulk materials of plant origin through the development of systems for automatic and automated control of the electrophysical characteristics of grain products and to increase the reliability of quantitative and qualitative assessments of production and technological measurement information. To achieve this goal, it is necessary to conduct analytical and experimental studies of the possibility of creating an express method for controlling the moisture content of grain and products of their industrial processing and the development of a moisture meter for automated control of raw material parameters during acceptance and storage at grain processing enterprises. The article discusses the scientific and methodological foundations for measuring the electrophysical characteristics of grain products of agricultural production and the implementation on this basis of the functional subsystem of information support by the Automated Process Control System for Controlling the Mass Ratio of Moisture of Plant Origin Materials. A critical analysis of the current state of the theory and practice of automatic control of electrophysical characteristics of grain products and the identification of the trend of their further development and improvement are carried out. A mathematical model of the interaction of a high-frequency field with a granular material has been constructed, where the influence of the elastic properties of the grain on the electrical characteristics of the electromagnetic wave, which distinguishes its behavior in the field of a high-frequency wave from many other dielectrics, has been substantiated, and the influence of a large number of various disturbing factors has been studied, often the measurement results cannot be applied in the control of the technological process due to the uneliminated error, which is the cause of inaccurate information. Primary measuring transducers of electrophysical parameters of grain products are proposed, and their mathematical models are considered. A functional scheme of the measuring device based on the dielcometric method of moisture control of grain and granular materials has been developed, and metrological characteristics have been given.

EXPERT ASSESSMENT OF THE THERMODYNAMIC STATE OF THE "METAL-SLAG" SYSTEM IN REDUCING AND OXIDIZING CONDITIONS

A new approach has been developed to assess the thermodynamic state of the "metal-slag" system in the production of cast iron and steel using the parameters of interatomic interaction. As a result of computational and analytical studies of the indicators of the melting products of the blast-furnace and steelmaking processes, the regularities of the coordinated change in the chemical compositions of the metal and slag melts were revealed. A close relationship has been established between the integral indicators of metal (ZY) and slag (, e), characterizing the chemical and structural state of their melts. As a criterion for evaluating the thermodynamic matching of melts of the "metal-slag" system when it tends to equilibrium, an analytical expression is proposed in the form , which can be implemented in automated process control systems to solve the problems of controlling the thermal and slag modes of iron production and steel of the required composition.

Обзор основных компонентов, особенностей и решений безопасности автоматизированных систем управления технологическими процессами

The structure, main components and tasks of typical automated process control systems (ACS) are described. The main distinctive features of automated systems and their impact on the design of an information security system (ISMS) are determined. A brief overview of the problems of information security of automated process control systems is given. The basic principles that must be taken into account when creating.

Моделирование работы газотурбинной установки SGT5-4000F с исследованием влияния режимных и климатических факторов на устойчивость горения в камере сгорания

When regulating gas turbine units, it is necessary to be confident in the stable combustion process in the combustion chambers, considering the dynamics of the processes and changes of external climatic factors. Many scientific studies are devoted to the problems of experimental research and mathematical modeling of processes in combustion chambers. The possibilities of flame failure, expansion of the lower limit of combustion, determination of the stable position of the flame front and other issues have been assessed. Even though the problem of design of mathematical models and their use remains relevant. The purpose of this research is to model and study the influence of operation and climatic factors on the stability of combustion in the combustion chamber of the SGT5-4000F gas turbine unit. The subject of the research is the SGT5-4000F gas turbine unit with a low-emission combustion chamber. The simulation model of the gas turbine unit has been developed in the environment of dynamic modeling of technical systems SimInTech. The research is carried out using theoretical methods of calculating fuel combustion, thermodynamic foundations of the theory of gas turbine engines, methods of mathematical and simulation modeling, as well as data from the archive of automated process control systems. A simulation model of SGT5-4000F gas turbine unit has been developed. It is distinguished by the ability to assess the proximity of the compressor operating mode to the stability limit and determine the boundaries of stable combustion procedure in the combustion chamber, considering environmental climatic factors. The authors have studied the stability of the compressor and combustion chamber. The results of the experimental studies of a gas turbine unit in the operating load range from 113 to 282 MW and in the range of outside air temperature from –12 to 30 °C have shown that the combustion process in the combustion chamber is unvarying over the entire operational stress spectrum. The results obtained are verified by comparing model values with technological parameters of a gas turbine unit taken from the archive of the power plant control system. The authors have assessed the influence of electrical load on the performance indicators of a gas turbine unit at outdoor temperatures of +30, +15 and –12 °C. According to the results of simulation modeling, the model of SGT5-4000F gas turbine unit is found to be adequate. The developed model can be used as a tool at the stage of functional and technological design of automated control systems for the development of effective automatic control systems.

New approach to evaluating the thermodynamic consistency of melts in the ‘metal-slag’ system based on interatomic interaction parameters


 
 
 The article presents a new approach to evaluating the thermodynamic state of the ‘metal–slag’ system during metal smelting in oxidizing-reducing conditions. The interaction between the metal and slag is analyzed using the model of the structure of metallurgical melts, which considers cooperative ion exchange processes and interatomic interaction parameters. As a result of analyzing experimental data on the compositions of reacting melts during pig iron and steel smelting, criteria were developed for assessing the degree of achieving the equilibrium in the system regarding sulfur. The charge state parameters of the metallic system ZY and the slag system Δe, the slag stoichiometry index ρ, and the charge state parameter of the melt components Zi were used. The regularity of a consistent formation of metallic and slag melts has been established, which is evidenced by a significant correlation between the chemical equivalent of the metal composition ZY and the slag Δe. Analytical dependences were obtained in the form of ZY = f (Δe, ρ). The identified patterns and criteria can be integrated into automated process control systems for regulating the slag regime and producing high-quality pig iron and steel.
 
 

CYBERSECURITY RISKS MANAGEMENT OF INDUSTRIAL CONTROL SYSTEMS: A REVIEW

Industrial control systems (ICS) form the basis of critical infrastructures, managing complex processes in various sectors of industry, energy, etc. With the increasing frequency and complexity of cyber threats, effective management of ICS cybersecurity risks is critical. This paper is devoted to the analysis of approaches used in the field of cybersecurity risk management of automated process control systems. The study examines the cybersecurity risks of ICS and the role of international standards in managing cybersecurity risks. The results of the analysis carried out in this paper can serve as information for the development of new reliable cybersecurity risk management systems for ICS.

PROBLEM STATEMENT AND MODELING OF AN ENERGY TECHNOLOGY SYSTEM FOR THE JOINT PRODUCTION OF SULFURIC ACID AND CONDENSED SULFUR DIOXIDE

The article develops a mathematical model for the quantitative assessment of technological parameters of energy-technological systems for the production of sulfuric acid and condensed sulfur dioxide. When modeling, the system was considered as energy-technological, taking into account the need to reduce its negative impact on the environment, due to both industrial emissions of harmful substances and emissions of unused thermal energy. In this regard, it was envisaged to process part of the sulfur dioxide according to a cyclic scheme. To increase the intensity of the technological system and the processes occurring in it, the use of oxygen and the provision of a high concentration of sulfur dioxide in the gas mixture before the stage of its catalytic oxidation in the contact apparatus was envisaged. To reduce the total volume of reactants, an increase in pressure in the system was assumed. The carried out formalization and object-oriented decomposition of the simulated system made it possible to identify 6 functional subsystems (blocks), each of which can be modeled and investigated independently. The accepted high level of formalization made it possible to include a minimum set of real system parameters in the model. The model is capable of development and can be concretized by introducing additional parameters and mathematical models of technological functions into consideration. The developed model is recommended to be used for operational modeling of combined systems for the production of sulfuric acid and condensed sulfur dioxide in the preparation and optimization of initial data for their design. After testing and setting up the model in practice, it can be used in an automated process control system, including when creating adaptive control systems.

Microservice information and management system for digitalization of document flow of APCS projects

A microservice information management system (IMS) that allows automation the preparing process of the required documentation for the developed projects of the automated control systems for technological processes (APCS) is proposed. The main requirements for digitalization of document flow of such projects are outlined. The functionality of all services implemented in the IMS is considered. A data storage method is determined that consider the specifics of storing not only structured information (for example, about specific equipment models, specialists, etc.), but also information about special JSON models used in the process of the service operation or calculating the configuration of an automated process control system project. The principle of forming documents on automated process control systems projects in the proposed IMS is shown. The work is aimed at increasing the efficiency of the development and deployment of automated process control systems projects for companies offering comprehensive solutions for technological processes automation at industrial enterprises. Keywords automatic control system for technological processes (APCS), information management system, microservice architecture, digitalization, document flow

Principles of Constructing a HIL Simulation Stand for Debugging Automated Process Control Systems based on the Baget PLC

The problem of constructing a HIL simulation stand for researching a technological process using programmable logic controller (PLC) "Baget" is described in this article. Issues of modeling technological processes are currently extremely relevant, since modeling is a mandatory stage in the automated process control systems development. An adequate model of the technological process allows debugging and verification of automated process control system algorithms without using real equipment, reducing financial costs and the probability of emergency situations. The HIL modeling method involves partial use of real equipment as part of the model. The inclusion of standard components of the original object in the model does not require detailed mathematical model and at the same time provides a more complete correspondence to the original. Due to using a computer from the original object, the stand software operates under conditions close to the real technological process, which improves the quality of the simulation results. The HIL modeling stand includes the following components: control computer of automated process control system; programmable logic controller PLC "Baget"; simulation computer. The stand for the basic element of an automated process control system allows to speed up the process of prototyping and debugging even in the case of complex systems, because it will be easier to build the entire system from correctly functioning elements. Another advantage of this approach is that the stand is not tied to a specific type of technological process or to a narrow area of production — the stand allows the use of ready-made models, the development of new models, and the inclusion of various function libraries. The simplicity of the stand design with this approach is combined with a full range of functionality. By connecting additional software, you can create more complicated and detaild model. This stand is also capable of serving both for debugging PLC algorithms and as a simulator for maintenance personnel of a real control object, because the stand operator can simulate failures and errors of standard equipment, emergency situations at the control object. Using C and JavaScript programming languages for development ensures portability and ease of expanding the capabilities of the modeling software. The development of complex systems based on HIL modeling allows saving resources and effectively solving assigned problems, therefore the proposed approach to building stands will be in demand in the process of developing an automated process control system based on the PLC "Baget".

Комплексная оценка трудноформализуемых вентиляционно-технологических процессов на угольных шахтах

Introduction. Automated process control systems, as a set of characteristics related to the ability of an object to satisfy certain needs, are one of the most important indicators of the quality of complex technical systems consisting of a large number of interacting mechanisms, apparatus and instruments. Their failure can lead to accidents and emergencies, resulting in large economic losses, destruction of industrial facilities, and sometimes human casualties. Methodology and research methods. The solution to the assigned problems is based on modern methods of artificial intelligence, automatic control theory, mathematical modeling of technological processes, and mathematical statistics; graph theory; decision theories; apparatus of mathematical logic; set theory and systems analysis. Discussion of research results. The article presents the results of studies of the patterns of ventilation and technological processes in coal mines. It has been established that studies of patterns in coal mines are becoming more relevant in connection with the formulation of the task of modernizing production and the Russian economy as a whole. It has been revealed that the methodological foundations for the synthesis of control decisions that ensure the achievement of a stable state make it possible to formulate acceptable organizational and managerial decisions and evaluate their effectiveness using metered characteristics of the proximity of vaguely described states. Conclusion. Based on the research carried out, new theoretical and applied problems were posed and solved, system connections and patterns of the ventilation technological process (VTP) were identified, models, methods and algorithms for automated ventilation technological process control systems (ACVTP) were developed, aimed at increasing the efficiency of the technical air supply system coal mines. The theoretical foundations for modeling and controlling ventilation and technological processes have been created, including concepts, models, methods and control algorithms. The research results can be useful in controlling ventilation and technological processes. Conclusions on the article. The article presents the results of studies of ETP conducted in coal mines. It has been established that, using the developed methodology, it is possible to: design high-tech equipment with specified quality indicators for intelligent control systems; choose from a variety of structural diagram options the best in terms of operational efficiency; carry out structural-parametric adjustment and change the types of mathematical models, both for an individual element and for the ETP as a whole; identify the weakest points in the HTP automated control system and adapt the methodology for controlling ventilation and technological processes, evaluate the effectiveness of using structural redundancy. Suggestions for practical applications and directions for future research. The research results can be useful when carrying out mining operations at all enterprises where air supply is necessary.

REVIEW AND CRITICAL ANALYSIS OF THE CURRENT STATE AND WAYS TO IMPROVE REGULATED POWER SUPPLIES AND AUTOMATIC CONTROL SYSTEMS FOR ELECTRIC CENTRIFUGAL PUMPING UNITS IN INTERMITTENT OPERATION OF OIL WELLS

Link for citation: Kladiev S.N. Review and critical analysis of the current state and ways to improve regulated power supplies and automatic control systems for electric centrifugal pumping units in intermittent operation of oil wells. Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 9, рр. 203-215. In Rus. Relevance. At present efforts are being made to convert low- and medium-flow oil wells to cyclical or short-term operation in order to reduce the excess pumping capacity that resulted from the reduction of well flow that is caused by reduced reservoir pressure during long-lasting exploitation of the deposit. The need for such a conversion requires justification for the use of more complex configurations of regulated power supply sources and automatic control systems of centrifugal pump units electric drives in automated process control systems. The local low-level automatic control systems for a mechanized electric drive method for lifting an oil-containing liquid from the well to the surface, namely the installation of variable-speed AC electric drives consist of ground-based devices and special submersible equipment. The ground-based devices are control stations with AC voltage and frequency converters with built-in telemetry units, external sine filter, step-up transformer. The special submersible equipment includes asynchronous induction electric motor, power cable, submersible telemetry unit, process sensors, centrifugal pump. The power supply of such a unit is provided from the external electric three-phase network of 6 kV through a reducing transformer substation of 6/0,4 kV. In the continuous mode of operation of oil pumping plants the electric pumps and other equipment, operate in quasi-static modes. Unregulated electric drive, as well as the open-loop controlled electric drive does not allow for smooth acceleration to the nominal performance of pumping equipment for pumping oil out of well in difficult conditions and its smooth regulation when reducing the well flow because of reducing oil flow to the slaughter. Therefore, the main way of smoothly reducing the excess performance of the submersible centrifugal pump is the periodic activation mode, which includes pumping the oil mixture out of the well and stop – for its accumulation and recovery of formation pressure. The introduction of cyclical technology shows that it is impossible to use the open-loop system of regulated electric drive everywhere, where acceptable quality indicators of transition comparable with the quality of closed-loop control systems are objectively unattainable. Due to the fact that the amount of pressure at the well intake created by a centrifugal pump, necessary to lift the well fluid to the surface, depends on the square of the rotation speed of the pump working stages, the operating pump productivity range Qmin... Qmax (m3/day) is obtained by varying the motor stator winding voltage (80…100) % from the nominal voltage value by using AC voltage controller with a phase control mode. If the stator voltage value is less than 80 % of Unom then the well fluid is not lifted to the surface and does not flow out of wellhead equipment. Therefore, when a frequency converter with Unom/fnom=const is used, the supply voltage and frequency of the motor should be varied in the same range. The price for using cyclic operation is a decrease in the reliability of submersible pumps. It is necessary to use special designs of submersible electric motors, improve power supply systems and synthesize closed-loop control systems of automatic control of electric drive of submersible pump. The purpose of the study is the review and critical analysis of the current state and ways to improve regulated power supplies and automatic control systems for electric centrifugal pumping units in intermittent operation of oil wells. Object: systems of power supply and automatic control of centrifugal pump units in intermittent operation of oil well, telemetry systems, energy-efficient submersible motors and centrifugal pump designs. Methods: methods of the theory of the automatic control system for developing the concept of operation of low flow of wells, analysis and synthesis of open and closed loop control systems of electric submersible centrifugal pumping units. Results. The paper introduces the scientific problem of development, implementation, models and methods of identification of technological processes, complexes and integrated control systems of oil extraction by electric drive method, taking into account the influence of a long submerged cable, low flow of wells and difficult operating conditions. The author proposed scientifically based technical solutions in the form of a structure of a power channel of an electromechanical system with a frequency-regulated induction motor, long submersible cable and indirect method of measuring state variable from ground-based measurements at load changes and measurement channel characteristics.

Intelligent Algorithms for Event Processing and Decision Making on Information Protection Strategies against Cyberattacks

This paper considers the main approaches to building algorithms for the decision support systems of information protection strategies against cyberattacks in the networks of automated process control systems (the so-called recommender systems). The advantages and disadvantages of each of the considered algorithms are revealed, and their applicability to the processing of the information security events of the UNSW-NB 15 dataset is analyzed. The dataset used contains raw network packets collected using the IXIA PerfectStorm software in the CyberRange laboratory of the Australian Cyber Security Centre (Canberra) in order to create a hybrid of the simulation of the real actions and the synthetic behavior of the network traffic generated during attacks. The possibility of applying four semantic proximity algorithms to partition process the data into clusters based on attack type in a distribution control system (DCS) is analyzed. The percentage of homogeneous records belonging to a particular type of attack is used as the metric that determines the optimal method of cluster partitioning. This metric was chosen under the assumption that cyberattacks located “closer” to each other in the multidimensional space have similar defense strategies. A hypothesis is formulated about the possibility of transferring knowledge about attacks from the vector feature space into a semantic form using semantic proximity methods. The percentage of homogeneous entries was maximal when the cosine proximity measure was used, which confirmed the hypothesis about the possibility of applying the corresponding algorithm in the recommender system.

The Decision-Making Technique Based on Computer Vision and Selection of Pareto-Optimal Alternative of Technological Production Parameters

The article proposes a decision-making technique in the field of rolling production process control based on the analysis of rolling tape surface image and the construction of technological parameter Pareto-optimal set. The substantiation of the automated process control system modernization scheme based on the introduction of a decision support system with computer vision for the rolling mill operator is presented. As a result of the technique development, the wavelet model of the rolling tape surface image is modified; the model presented in the pixel packet form; the classification information field has been expanded to improve recognition accuracy of rolling tape surface defects; the algorithm for forming the defect region and refining spatial features was developed; the algorithm for the construction of technological production parameter Pareto-optimal set has been developed. The application of the proposed technique made it possible to increase the accuracy of the rolling process control.

A method for searching the best static program for nuclear power unit control in the event of perturbations of different nature

Considering the current state of Ukraine's energy sector in a dangerous and unstable environment, the operation of nuclear power plants is one of the most important sources of electricity supply for the state. The development of the theory of optimal control and the technical level of automated process control systems in the current state of affairs make it possible not to reduce the efficiency of controlling a nuclear power unit, not only by changing the parameters at any load, but also by changing the structure of automation equipment capable of implementing a certain static control program of power, which currently eliminates the influence of internal and external disturbances, without reducing safety indicators. The article considers the situation when the linear programming method is not applicable for solving the control problem. In this case, the decision at each stage does not depend on the decision at the previous one. This is where target programming comes in handy –this is one of the methods of multi-criteria optimization, in the theory of which decision-making problems are solved simultaneously according to several criteria. The purpose of the work is to ensure the safe and efficient operation of a nuclear power unit in an energy system that is not constant in operational states. Using a mathematical model of a nuclear power unit, experiments were carried out to simulate the switching of controlprograms. The simulation model of the automated power control system, based on the bumpless switching of static programs according to the technological methods of operating power equipment, made it possible to form a change in the current model of the control program, as well as eliminate the static control error and get the response of process dependent parameters to program switching. Also, based on the results of the research, an objective function was proposed, which includes three normalized criteria with different objectives. In particular, the problem of optimizing the switching of static power control programs was solved by minimizing the objective function, which combines such characteristics as the efficiency and safety of the operation of a nuclear power unit.

Опыт освоения магнитно-гравитационной сепарации на предприятиях России и стран СНГ для повышения качества железорудного сырья

The paper analyzes the tasks of producing high-quality iron ore concentrates suitable for nonblast-furnace metallurgy and the challenges of processing magnetite ores with the current technological level of dressing equipment and technologies. One of the best methods to improve the quality and the grade of iron ore raw materials is the use of magnetic gravity separation in the technological process, which allows selective separation of the liberated magnetite particles from their aggregates in processing of undersize products of fine vibrating screening. This trend is implemented in the innovative magnetite ore processing technology that uses the principle of the staged output of finished concentrate. The technology makes it possible to produce a high-quality concentrate after the first grinding stage. The magnetic gravity separation has undergone industrial validation, has proven its efficiency in practice, and has become widespread at mining and processing plants not only in Russia, but also in the CIS countries. Over 180 MGS-2.0 magnetic gravity separators produced by Russian manufacturers have already been or are being implemented at various Russian and CIS companies. Industrial separators are equipped with modern automation systems providing high technological separation performance, have no rotating parts and are simple in design. The authors continue R&D works on creation of automated control systems for the magnetic gravity separation process based on designing digital models adapted for introduction into the plant’s automated process control systems.

Signal device for motor grader

Problem. Automated machines play an important role in modern construction, improving productivity, quality and safety. A signal device for road construction machines plays an important role in ensuring the efficient performance of road works. It relieves the driver of the need to continuously monitor the devices and controls of the motor grader. In this work, a signal device was proposed for continuous monitoring of the devices and controls of the motor grader. Goal. As a result of the analysis, the purpose of the study was highlighted: to design a signal device for a motor grader. Job tasks: to design a signal device for continuous monitoring of the motor grader's devices and controls. Methodology. Аutomation of construction and road machines is carried out mainly in three areas, which provide control of the spatial position of the working bodies of machines, optimization of the most energy-intensive modes of machine operation and the creation of a laser-based integrated automated process control system in construction. It was decided to design a signal device with different tones and sound effects Results. The result of the study is the design of a signal device for continuous monitoring of devices and controls of a motor grader, which makes it easy to determine the state of the controlled controls of the motor grader, even when performing several functions simultaneously. Originality. The originality lies in the fact that the signal device has different tones and sound effects (trill, siren), which make it easy to determine the state of the motor grader's controlled controls. Practical value. The signal device performs three functions: signal the height position of the blade relative to the plane necessary for the transportation of the motor grader; signal the critical angle of the blade turn relative to the direction of the motor grader; signal the critical transverse inclination of the blade.

EXPERIMENTAL RESEARCH CHARACTERISTICS OF TRANSFORMATION BY THE OPTIC-ELECTRONIC MODULE OF THE AUTOMATIC CONTROL SYSTEM

Simulators of environmental state sensors are used to set up and control the efficiency of automatic process control systems. In some cases, it is convenient to use a voltage-resistance converter with an optoelectronic output module based on a controlled photoresistor as a simulator of potentiometric sensors.
 An optical-electronic voltage-to-resistance converter, which has a galvanic isolation of the output and has a linear characteristic in a given range of output resistance is developed. The developed converter allows to set the angular and free coefficients of the linear equation arbitrarily that describes the response function of the converter and correctly simulate the operation of a potentiometric state sensor of the controlled parameter. An operating model of the converter was developed and manufactured, experimentally determination of its response function for different values of the free coefficient, supply voltage and different options for the circuit design of the optoelectronic module was carried out.
 The principle of operation of the converter is based on a change in the resistance of photoresistors under the influence of optical radiation coming from a controlled source. The model of the converter consists of optical and electronic blocks. The optical block consists of an optical radiation source and two photoresistors simultaneously directed at it. The signal from one photoresistor is the output, and the signal from the second photoresistor is analyzed by the control circuit, which synchronously changes the illumination on the light-sensitive areas of the photoresistors through the brightness controller in accordance with the voltage level of the control and corrective signals.
 The experimentally determined response function of the converter in the initial section has a non-linearity in the zone of low input voltages, which is determined, foremost, by the limitation of the lamp brightness and depends on the scheme of its inclusion. The non-linearity zone in the researched converter can be significantly reduced by increasing the supply voltage. Within the given range of change of the output resistance of the rectilinear section of the response function, the output resistance of the converter is linearly related to the input voltage, according to the results of experimental measurements in natural laboratory conditions, the conversion error hasn’t exceeded 0.3%.

Improvement of monitoring and control system for copper electrolytic refining parameters

The utilization of modern automated control systems in copper cathode production offers the opportunity for remote access to control and regulate the electrolytic process parameters. This, in turn, enhances production efficiency while reducing energy costs. The significant parameters in copper electrolytic refining encompass the temperature and composition of the electrolyte, the circulation rate of the electrolyte, the level of sludge, and the frequency of short circuits occurring between the electrodes and the current density. These parameters directly impact the quantity and volume of cathode sludge. The occurrence of short circuits within the bath arises from the growth of dendrites, necessitating the monitoring of voltage, composition, and temperature of the electrolyte. Regular analysis of the electrolyte's composition and the accumulation of sludge volume at the bottom of the electrolyzer is also necessary. The intensification of the electrolysis process primarily involves increasing the current density, reducing the electrode spacing, enhancing the quality of electrodes, improving the electrolyte circulation system, and further mechanizing and automating the process and its auxiliary operations. These efforts contribute to increased productivity. The objective of this study is to expand the capabilities of automated process control systems by incorporating sludge level control sensors. This aims to mitigate irrecoverable losses resulting from dendritic sludge short circuits on the electrodes located in the lower section of the electrolyzer, utilizing new software. A sludge level control method to prevent short circuits has been investigated, and control software employing float-type level sensors has been developed. This measure is projected to decrease energy consumption by 15–20 % and can be effectively implemented in the production of electrolytic copper at the copper smelting plant in Lao Cai, Vietnam.