Operation Control System Research Articles

A Novel Virtual Voltage Comparison Compensation for Dynamic Voltage Restorer

In view of the high-quality requirements of the power supply quality of the user-side sensitive equipment, the system for voltage sag in the grid operation is stable and efficient. This paper proposes a new virtual voltage comparison compensation dynamic voltage recovery method. The algorithm that uses the invariant constant signal as the input quantity, and the real-side input load side signal reduces the influence of the input quantity uncertainty change on the generated compensation signal and improves the simplicity of the system operation control and the system stability. The flexibility of the proposed control strategy, as well as the effectiveness of the optimal design method, is verified by both simulation and experimental results.

Solving a reliability-performance balancing problem for control systems with degrading actuators under model predictive control framework

In this paper, we formulate and study a reliability-performance balancing problem (RPBP) for long-term operational and unattended control systems with degrading actuators. It preliminarily explores a new type of autonomous maintenance method to extend the useful lifetime of the control system. The actuator, as the crucial component of a control system, executes calculated control actions and thereby is often exposed to the high-load working environment. As the actuator degrades, the control action will gradually alter with increasing magnitude to maintain the desired control performance, but this will accelerate the actuator degradation and thus reduce the useful lifetime (use reliability) of the control system. Therefore, conditionally balancing the control performance and use reliability is meaningful, for which a novel dynamic regulation strategy under the model predictive control (MPC) framework is proposed. Specifically, we model the actuator degradation using a diffusion Wiener process coupled with the control action or system state, and the corresponding actuator reliability is derived. By fusing the degradation model and system dynamics, a degradation-incorporated state space (DISS) model is formulated, in which the basic idea is to consider the actuator degradation as an extended state variable and to control it accordingly. Based on the DISS model, a mixed-index nonlinear MPC integrated with a weight tuning strategy is proposed to achieve a satisfactory balance between control performance and use reliability in the presence of actuator degradation. Further, the reference curve and the upper bound of actuator degradation are given for constructing the objective function and the constraint in the MPC optimization problem. An illustrative example is presented to demonstrate the availability of the proposed method.

Design and comparison of two advanced core control systems for flexible operation of pressurized water reactors

This paper focuses on the design of advanced core control systems for future generations of pressurized water reactors. The objective is to improve the flexibility of nuclear power plants to cope with the rapid growth of renewable energies. In practice, this means that the average coolant temperature, the axial power distribution of the reactor core and the position of the control rods have to be properly regulated during power variations. In previous work, conducted by the same authors, two promising approaches were investigated: 1) fixed-structure gain-scheduled control and 2) nonlinear model predictive control. Here, both methods are tested according to industry standards in an attempt to determine the best one for our problem. To achieve this, two different controllers are designed using a new multipoint kinetic model of the reactor core, which provides an accurate representation of the axial power distribution. The advantages and drawbacks of both design methodologies are discussed and then compared on PWRSimu, an intermediate complexity pressurized water reactor simulator developed by Framatome.

Research and Application of Haar Wavelet Transformation in Train Positioning

With the continuous increase of the urban population, urban traffic problems have become increasingly prominent. The subway and light rail have the characteristics of large passenger volume and low pollution, which are the preferred solutions to solve the traffic problems in large and medium cities. Due to the high density of rail transit trains, the close distance between stations, and the high safety requirements, the real-time and accurate determination of the train's position on the line is the premise to ensure safety, maximize efficiency, and provide the best service. How to accurately detect the speed and position of the train to control its the operation is the core content of the rail transit system. Therefore, the in-depth study of train positioning methods has great and far-reaching significance for promoting the research of train operation control system and the development of rail transit system. It has become a research hotspot to rely on computer technology and image recognition technology to realize precise positioning of trains. In order to realize the real-time precise positioning of the train, this paper proposes a train positioning method based on Haar wavelet transform. First, the samples are obtained by the method of video acquisition, and the video images are initially processed by binarization. Second, the image is compressed, denoised, and enhanced by Haar wavelet transform, and the train number is determined. Finally, the orbital electronic map and satellite assistance are used to determine the position of the train and realize the train positioning. The simulation experiments show that the image acquired by Haar wavelet transform can accurately identify the train and track. Based on the satellite aid of the orbital electronic map, the train positioning can be accurately realized, and the proposed Haar wavelet transform is proposed and has good positioning accuracy.

Risk identification of civil aviation engine control system based on particle swarm optimization-mean impact value-support vector machine

The actual risk of the engine control system in operation is often higher than expected risk level, which brings hidden dangers to the safe operation of aircraft. Therefore, a PSO-MIV-SVM (particle swarm optimization-mean impact value-support vector machine) model is proposed to identify the risk of engine control system. Firstly, seven characteristic variables are extracted through the analysis of engine unsafe information, and 810 typical engine event samples were selected and normalized. Secondly, the SVM-based engine control system risk identification model is established and optimal kernel function of the SVM model is selected. Thirdly, the SVM-MIV method is used to sort the importance of the seven characteristic variables, and the identification accuracies of different characteristic variable groups are calculated to obtain the optimal combination of characteristic variables. Finally, the parameters of the SVM model are optimized by using the PSO algorithm and the accuracy of the PSO-MIV-SVM model for the risk identification of the engine control system reaches 93.58%.

Study on auxiliary operation control of machine learning in multiobjective complex drainage system.

Recently, urban waterlogging prevention and treatment of black-odorous rivers have become a social concern and the upgradation of drainage system and the development of river runoff pollution control projects have accelerated. The use of deep tunnels to upgrade old drainage systems and achieve pollution control-related engineering designs has complicated the drainage system operation control. The traditional operation control mainly relies on human experience or model simulation. This study provides a perspective of machine learning for controlling the operation of the drainage system and exploring whether the operation suggestions regarding facilities in this system can be given in real time while relying only on real-time data and avoiding the complex model simulation process. Herein, five drainage systems were used as examples: the initial water level of a pipeline, key point water level flow, pump station front pool water level, and most unfavorable point water level were selected as relevant variables and four machine-learning discrimination methods were used for to analyze the weir-lowering operation of a deep tunnel. This study found that the average error rate of the linear discrimination method was <10%, thereby exhibiting satisfactory performance. This study provides insights for improving the operation of complex drainage systems.

Strategy Selection in the Implementation of PT Kereta Commuter Indonesia's Security Management System in The Greater Jakarta Area

The purpose of this study is to describe a general description of the conditions of Security Management System (SMS) implementation in the PT KCI Greater Jakarta area, examine indicators that can affect the implementation of SMS at PT KCI Greater Jakarta area, and formulate a priority scale strategy for SMS at PT KCI Greater Jakarta area during the COVID-19 pandemic. The researcher uses Analytical Hierarchy Process (AHP) method by including six indicators of field certification, employee skills training, reporting &amp; administration, archive documentation, and performance evaluation as the selection of indicators that affect implementation, and three alternative selection strategies, namely training competencies, documentation &amp; records, and controls &amp; processes. The results showed that the most influential indicators were the Documentation Archive 0.331, Reporting &amp; Administration 0.223, and Operational Control 0.203, while the appropriate alternative strategies to determine steps in implementing SMS during the covid-19 pandemic were Documentation &amp; Records 0.594 and control and process 0.262. The results imply that to achieve the successful implementation of the SMS program at PT KCI, a document filing system and good operational control are needed in each security unit.

Variable operation of a renewable energy-driven reverse osmosis system using model predictive control and variable recovery: Towards large-scale implementation

Powering Reverse Osmosis (RO) systems with Renewable Energy (RE) is essential for decarbonising water production. Integration of RE requires large-scale RO plants to operate efficiently using variable power. Nevertheless, variable operation (involving matching the RO load to available power without battery back-up) has only been implemented for small-scale systems. This paper presents a variable-speed operation technique suitable for large-scale RO systems using an optimised operational strategy and a Model Predictive Controller (MPC). The technique was validated using a laboratory test rig having comparable performance to large-scale systems. A dynamic plant model was used to design the operational strategy and control system. Several operational strategies were explored for varying the operating parameters according to power available from a RE source. An advanced control system based on MPC was designed and compared to a conventional Proportional-Integral-Differential controller. The results showed that operation at variable recovery with constant brine flowrate delivered the lowest specific energy consumption and widest operation range for a system with an isobaric pressure exchanger. The MPC controller improved the settling time for a 10% step-change in permeate flowrate by 47%. Moreover, it improved energy utilisation, giving a 2.35% increase in hourly permeate production for a defined power input time-series.

Multidimensional Heterogeneous Network Link Adaptation Based on Mobile Environment.

With the development of communication technology, train control operation system develops gradually, which significantly improves the reliability and efficiency of train operation. The current mobile Internet has gradually highlighted the many limitations of the mobile Internet in the high-speed mobile environment, which seriously deteriorate the service quality and user experience, and cause a waste of resources. In order to meet the real-time requirements of network communication resource scheduling in the mobile environment, aiming at the multidimensional dynamic adaptation framework constructed in a mobile environment, a service and network adaptation mechanism based on link failure state prediction is proposed in the paper. First, cross-layer theoretical analysis and actual data analysis are combined to construct a wireless link failure probability model. Then, reliable transmission requirements and transmission overhead are applied to optimize goals. Finally, simulation experiments are carried out according to the railway network data to evaluate the E-GCF adaptation algorithm. The experiment results show that compared with the current mainstream algorithms, the prediction accuracy of this adaptation algorithm is improved by 25%. The execution time of the algorithm is reduced by 9.6 seconds and the successful submission rate is as high as 99.99%. The advantages of the algorithm are significantly superior other algorithms. It proves that the research method of this paper can effectively improve the satisfaction rate and utility value of reliable transmission, as well as enhance the throughput performance. It solves the adaptation problems of frequent switching and low utilization of heterogeneous networks in a mobile environment, which contributes to the high-quality communication service of mobile network.

Completion of JT-60SA construction and contribution to ITER

Construction of the JT-60SA tokamak was completed on schedule in March 2020. Manufacture and assembly of all the main tokamak components satisfied technical requirements, including dimensional accuracy and functional performances. Development of the plasma heating systems and diagnostics have also progressed, including the demonstration of the favourable electron cyclotron range of frequency (ECRF) transmission at multiple frequencies and the achievement of long sustainment of a high-energy intense negative ion beam. Development of all the tokamak operation control systems has been completed, together with an improved plasma equilibrium control scheme suitable for superconducting tokamaks including ITER. For preparation of the tokamak operation, plasma discharge scenarios have been established using this advanced equilibrium controller. Individual commissioning of the cryogenic system and the power supply system confirmed that these systems satisfy design requirements including operational schemes contributing directly to ITER, such as active control of heat load fluctuation of the cryoplant, which is essential for dynamic operation in superconducting tokamaks. The integrated commissioning (IC) is started by vacuum pumping of the vacuum vessel and cryostat, and then moved to cool-down of the tokamak and coil excitation tests. Transition to the super-conducting state was confirmed for all the TF, EF and CS coils. The TF coil current successfully reached 25.7 kA, which is the nominal operating current of the TF coil. For this nominal toroidal field of 2.25 T, ECRF was applied and an ECRF plasma was created. The IC was, however, suspended by an incident of over current of one of the superconducting equilibrium field coil and He leakage caused by insufficient voltage holding capability at a terminal joint of the coil. The unique importance of JT-60SA for H-mode and high-β steady-state plasma research has been confirmed using advanced integrated modellings. These experiences of assembly, IC and plasma operation of JT-60SA contribute to ITER risk mitigation and efficient implementation of ITER operation.

An adaptive multiagent control system for autonomous economic operation and resilience assurance in a hybrid-energy islanded microgrid

Multi-agent control is widely recognized as an effective management system for modern microgrids. This paper proposes a hierarchical distributed multi-agent control system for an islanded microgrid with hybrid-energy resources and a battery-storage bank. The dispatchable dispersed generators are to be online-controlled to stabilize the islanded microgrid and minimize operation cost. A non-dispatchable agent is assigned to each bus with a non-dispatchable generator or a load. A dispatchable agent is assigned to each bus with a dispatchable generator. The control scheme is organized into three layers. The primary control layer comprises only the agent which runs the very fast local voltage/frequency droop-control of the battery-storage bank. It achieves a quasi-instantaneous power balance under any disturbance to maintain the frequency and voltage stability of the microgrid. The secondary control layer is formed by fast control algorithms on the dispatchable agents working at 2 ms time step. It is responsible for regulating the islanded microgrid frequency and voltage at minimum participation time of the battery-storage bank. The tertiary control layer is made by relatively slow control algorithms on the dispatchable agents working at a time step of 200 ms. It copes with the economic operation of the microgrid. Each agent behaves autonomously and shares data with others via communication links. The architecture and control algorithms of each layer are presented. Besides, the coordination protocol between different layers is described. The scheme is implemented by a parallel Matlab-Jade computing setup. Results of a case study islanded microgrid are analysed and compared to literature.

Monitoring of Objects Urban Gardening. Information System «Quality Management of Urban Sites Greening»

Monitoring of landscaping objects is a system of operational control over the violation of their stability, damage by pests, damage to diseases and other natural and anthropogenic factors of the environment, as well as a system for tracking the dynamics of these processes, which provides early detection of the unfavorable state of plantings, assessment and forecast of the development of ecologically unfavorable situations, obtaining reliable information about undesirable changes in nature under the influence of anthropogenic impact and materials for substantiating and making timely decisions. The article presents an algorithm for the formation of the information and analytical system “Quality management of urban landscaping objects”. At the first stage in the monitoring process, the tasks of observation and data acquisition are solved, such as: substantiation of the number and location of permanent observation sites in the city plan, which should be maximally represented in all zones of the city and in all categories of green areas; thematic mapping; creation of an information model. Approbation of the formation of a passport for the planting object of these techniques is presented on the example of a park in Krasnoyarsk.

Typology of individual values of combatants of the War in Eastern Ukraine

The individual values of combatants determine life goals, how to achieve them, and perform an important adaptive and protective function under conditions of combat stress. Understanding them enables mental health professionals to create an effective system of Combat and Operational Stress Control for military personnel. The purpose of this research was to determine the personal value sphere typology of individual values of combatants of the War in Eastern Ukraine, and, on its basis, to predict the vector of PTSD development. The value sphere (Rokeach Value Scale) and peculiarities of mental status (“Traumatic Stress Questionnaire”) of nine hundred forty three Ukrainian combatants were investigated. Cluster analysis made it possible to create a typology of combatants' values, consisting of five types: “Passionary”, “The one who does not leave the comfort zone”, “Romantic”, “Formal military man”, “Routine”. The most resistant to combat stress are combatants who are aimed at interiorizing values, expanding the boundaries of existing norms, and public recognition (“Passionary” (2.19%), “Romantic” (3.82%)), and the most vulnerable are those who are “Routine” (15.30%) and “Formal military man” (4.37%). The majority of Ukrainian combatants have a defined type of “The one who does not leave the comfort zone” type (74.32%). For them, safety and well-to-do life are the main priorities.

Conveyor belt regulator through silo operation

Conveyor belts are used in industries such as electro-mechanical and mechanical assembly to transfer goods from one position to another or from one procedure to another. In coal mining industries, controlling the speed of a conveyor can be achieved by controlling the speed of its drive unit. The Programmable Logic Controller (PLC's) commonly used programming language has the trapezoidal chart language, Ladder Diagram (LD), the Smooth Functional Diagram (SFC), and the Function Block Language (FBD). The four-level leather belt conveyer control system belongs to the model of sequential control and therefore mainly uses the SFC to program. A Programmable Logic Controller (PLC) is used to implement the control strategy. A PLC is a microprocessor-based control device with the original drive of complementing relay logic. The latest PLCs have progressed past just a robust stage into a new realm of high computational control and processor speediness. These, along with the PLC's extremely elastic arrangement, make it an ideal stage for uses far beyond its conventional ones. The main aim of this paper is to design a PLC conveyor belt control system for silo operation that has three various modes, namely continuous mode, manual mode, and fill by pass mode. The conveyor belt plays a very effective role as it reduces the time required to complete a large amount of work and increases productivity with high efficiency. It also saves money and costs, reduces the required manpower, is characterized by ease of maintenance and handling, and offers many other benefits.

Cyber resilience models of systems for monitoring and operational dispatch control of electric power systems

Systems for operational dispatch control (ODC) and monitoring of electric power systems (EPSs) are critical infrastructures that are strongly interrelated with a process part of the cyber-physical EPS and characterized by vulnerability to cyberattacks. As a result, the cybersecurity risk increases with a loss of EPS control to follow as the damage The issues of cyber resilience of such systems come to the fore. In this regard, a model of cyber resilience has been proposed, and an algorithm has been developed to qualitatively assess the cyber resilience index of EPS operational dispatch control system (ODCS) during cyberattacks on data collection, processing and transmission systems based on fuzzy logic tools and reliability theory. The study shows that factors such as the suppression of cybersecurity threats, adaptation and recovery of the system in case of cyberattacks affect the cyber resilience of the ODCS. The cyber resilience index is determined considering the cybersecurity risk, which is important when designing measures to increase the cyber resilience of EPS ODCS.

Postacute-Stroke Management Problems in Home Care Service: A Qualitative Single-Centered Study in Yogyakarta, Indonesia.

Objective This study explores the postacute-stroke management problems, particularly for patients with total dependency (Barthel Index <20), in home care service of Dr. Sardjito Hospital (SH) from the hospital personnel's and caregiver's points of view. Materials and Methods In-depth interviews with a semi-structured interview guide were conducted with hospital personnel and patients' caregivers based on the purposeful sampling. There were 10 hospital personnel that were interviewed: the director of medical service, head of home care unit, neurologists, general practitioners, nurses, and physiotherapist. There were eight caregivers who participated in the study. Statistical Analysis Data from the interviews were analyzed using systematic text condensation using Nvivo 12 plus. Results Our findings showed that all health personnel in SH agreed that home care service is a part of an integrated health care service for continuation of care. However, the preparedness by the hospital management is still lacking in infrastructures, such as standardized operational procedure, quality control, and financial system, as well as in terms of competent human resources and their welfare. In addition, the patient's family and caregiver are lacking in knowledge and independency to take care of the patients with the need of home care services' monitoring to deliver the expected home care for postacute-stroke's patient regularly. Conclusion Home care service is an act of implementing hospital obligation to fulfill the patients' rights. An established hospital policy to ensure a comprehensive home care service delivery is necessary. The capability and welfare of the health care personnel should be put into account for the standardized human resources.

Оценка киберустойчивости системы оперативно-диспетчерского управления ЭЭС

The research objective is to develop an algorithm for assessing the cyber resilience of the operational dispatch control (ODC) system of electric power system (EPS) during cyberattacks on data collecting, processing, and transmitting systems. The research methods include the probabilistic methods, fuzzy set theory methods, and methods of EPS reliability analysis. Result of the research: the impact of cyberattacks on the functionality of the EPS ODC system is analyzed. The factors ensuring the cyber resilience of the EPS ODC system in the case of materialization of cyber threats are identified. A model of cyber resilience of the EPS ODC system is proposed. An algorithm for assessing the cyber resilience of the EPS ODC system is developed factoring in the cybersecurity risks.

Study on Dynamic Model and Dynamic Characteristics of Solar Field of 50 Mw Trough Solar Thermal Power Generation Plant

Solar thermal power generation solves the problem of fluctuation and intermittency through energy storage system, and can bear the basic power load and peak load regulation. It is an important technical way for China's energy structure transformation. As a complex thermal system with multivariable disturbance, large inertia and large delay, the operation control of the solar field is a difficult issue. In this paper, the solar field of the first 50 MW trough solar thermal demonstration power plant in China is taken as the research object. Based on the topological structure and working principle of the solar field and the basic laws of optics and thermodynamics, the hydrodynamic calculation model and the heat transfer dynamic model are developed. The correctness of the model is verified by comparing the simulation results with the actual operation data. On this basis, the disturbance simulations are carried out. In addition, the dynamic response curves of step disturbance and the inertia time constant of the heat collecting loops are obtained. The conclusions of this paper have important guiding significance for the operation control strategy formulation and system optimization design of trough solar thermal power generation system.

Research on the Prediction of Energy-saving Potential of Traffic Tunnel Based on BP Neural Network

Accurate grasp of underground building environmental temperature and humidity and cooling and heating loads is the basis for energy-saving analysis, ventilation and air conditioning system design and operation control. In order to come up with a method that can quickly and accurately predict the environmental temperature and humidity and energy-saving potential of underground power station traffic tunnel, this paper takes Xiangyou pumped storage power station traffic tunnel as the research object and designs a BP neural network model for traffic tunnel temperature and relative humidity prediction with respect to the main environmental influencing factors. Comparing with the test data, it is verified that the model has high prediction accuracy. At the same time, the prediction model was used to calculate the energy saving potential of traffic tunnel ventilation. The results showed that the relative error of predicting the energy saving potential of traffic tunnel in summer was less than 2% and in winter was less than 0.3%. This prediction method can obtain the traffic tunnel air temperature and humidity and ventilation energy saving potential simply and accurately, so that the design can be developed in the direction favorable to the energy saving of underground buildings.

ОПЕРАТИВНИЙ КОНТРОЛЬ ПРОЦЕСУ ПЕРВИННОЇ ПЕРЕРОБКИ ВУГЛЕВОДНЕВОЇ СИРОВИНИ

The article considers the ways to solve the problem that arises during the primary processing of hydrocarbon (oil, gas condensate, etc.) raw materials and in the technical literature is called: "the fraction superposition effect". This problem is related to the use of technological equipment, including distillation columns, and can be solved by operational control and regulation of technological parameters (temperature, pressure, amount of fusion, etc.) of the process of separation of hydrocarbons into fractions. Operational control of the raw material division into fractions should be based on a system that includes a unit of operational control of technological parameters (quality indicators of distillate fractions) and a correction unit that allows immediate adjustment of parameters to the required level to ensure a certain quality of products. Primary information on the qualitative characteristics of the obtained fractions, in particular the content of impurities (X, %) of lower-boiling components of another fraction, should come from sensors located on the pipelines of the main material flows coming from the distillation column. As controllable indicators for determining (X, %), it has been proposed to use the indicator of relative permittivity – a measure of electrical properties of both raw materials and obtained fractions, supplemented by values of physicochemical parameters such as density and kinematic viscosity. It has been experimentally established that the increasing of the content of impurities in the studied fractions of adjacent fractions with lower boiling points leads to a decrease in the values of all mentioned indicators. Based on these data, a multiple regression equations were obtained, which adequately (R2 = 0.9847 ÷ 0.9969) with an error of 0.5-1.3 % can determine the values of X in adjacent fractions. The obtained equations, in turn, allow to quickly determine the effect of the imposition of compatible fractions, which can be used in the implementation of the system of operational control of the rectification process at the hydrocarbons primary processing plants. Keywords: hydrocarbon raw materials, rectification, fractions, superposition, low-boiling impurities, operational control, dielectric constant. Corresponding author A. B. Grigorov, e-mail: grigorovandrey@ukr.net