System In Different Modes Research Articles

Research on coordinated control technology of hybrid energy storage under grid-connected/off-grid dual mode

Abstract Aiming at the multi-time scale intermittency of renewable energy in microgrids and frequent power fluctuations will lead to a series of power quality issues. So, it is necessary to propose appropriate strategies for controlling the energy storage systems of microgrids to ensure energy balance. In microgrids, two types of battery energy storage are used to form a hybrid energy storage system, namely, zinc-bromine flow battery for energy storage and lithium titanate battery for energy storage. By analyzing the functionality of various energy storage systems in the grid-connected/off-grid dual style, the operation objectives of the hybrid energy storage system in different modes are proposed. In the meantime, the control strategy is formulated by combining the smoothing fluctuation characteristics of power-type energy storage and the peak load shifting features of energy-type energy storage. Finally, the efficiency of the hybrid energy system control strategy is checked by the simulation software in the connected/off-the-grid mode.

Automated air pressure control system in a motorised breathing apparatus

The relevance of the study is to develop an effective system for controlling the pressure in the air supply in motorised breathing apparatus to ensure effective protection of employees from dangerous aerosols and improve their health. The goal was to create an automated air pressure control system in a motorised breathing apparatus using a proportional-integral-derivative controller. For this purpose, the simulation method was used. In order to avoid unforeseen situations of deterioration of the level of protection, the structure of the pressure control system of a motorised respirator has been developed with the selection of the appropriate controller based on the obtained dependences of the influence of the parameters of the breathing mode and the amount of pressure in the under-mask space of the respirator, which ensures an appropriate comfortable mode of operation. This allowed developing a simulation model with a PID controller that would provide the appropriate pressure values within the permissible limits (50-370 Pa). It is proved that the proportional-integral-derivative controller maintains the pressure in the respirator mask within certain limits both with an increase and with a decrease in the control signal, preventing excessive fluctuations in the controlling variable, which leads to an extension of the service life of the filter elements and a reduction in electricity consumption for the operation of the fan motor. Based on modelling the operation of the pressure control system in different modes of operation, it is shown that when using a PID controller with defined parameters, the system provides compensation for changes in air pressure in the under-mask space of the respirator in different breathing modes of the user. The results can find practical applications in the field of safety and health, in industrial environments where workers are at risk of inhaling dangerous aerosols, such as toxic particles, gases, or other harmful substances

ОСНОВНІ ЕТАПИ ПОБУДОВИ ІМІТАЦІЙНОЇ МОДЕЛІ

The article examines the issue of the essence of simulation modeling. As the complexity of systems and processes across various sectors continues to grow, the ability to construct accurate and effective simulation models becomes increasingly important. Understanding the key stages of building an imitative model is crucial for ensuring the model's validity, reliability, and relevance to real-world scenarios. These stages typically involve problem definition, data collection and analysis, model design, validation, and implementation. Each stage requires careful planning, expertise, and attention to detail to ensure that the model accurately represents the system being studied. In today's fast-paced and competitive environment, organizations and decision-makers rely on simulation models to analyze complex scenarios, evaluate strategies, and make informed decisions. Therefore, having a clear understanding of the key stages of model building is essential for leveraging simulation modeling effectively as a decision-making tool. Furthermore, advancements in computational technologies and software tools have made it easier than ever to build complex simulation models. However, this also introduces challenges related to data quality, model complexity, and validation. Thus, knowledge of the key stages of building an imitative model is crucial for addressing these challenges and ensuring the model's accuracy and reliability. It is noted that the advantages of simulation modeling include the high adequacy of the model to the physical properties of the object, the possibility of a detailed description of complex systems, the research area that exceeds the capabilities of analytical modeling, the absence of restrictions on the display of dependencies in the model, the possibility of evaluating the functioning of the system in different modes, as well as obtaining extensive information about the object. It is emphasized that the sequence of building a simulation model involves the following steps: definition of the problem and its analysis; determination of information requirements; information gathering; proposing hypotheses and accepting assumptions; establishment of the main content of the model; determination of parameters, variables and efficiency criteria; description of the conceptual model and verification of its plausibility; construction of a logical structural diagram (block diagram).

Multicriteria Parametric Optimization of Nonlinear Robust Control with Two Degrees of Freedom by a Discrete-Continuous Plant

A multicriteria parametric optimization of nonlinear robust control with two degrees of freedom by a discrete-continuous plant has been developed to increase accuracy and reduce sensitivity to uncertain plant parameters. Such plants are mounted on a moving base, on which sensors for angles, angular velocities and angular accelerations are installed. To increase the accuracy of control, systems with two degrees of freedom, which include control with feedback and a closed-loop, and with direct connections and open-loop control of the setting and disturbing effects, are used. The multicriteria optimization of nonlinear robust control with two degrees of freedom by a discrete-continuous plant is reduced to the solution of the Hamilton-Jacobi-Isaacs equations. The robust control target vector is calculated as a solution of a zero-sum antagonistic vector game. The vector payoffs of this game are direct indexes performance vector presented in the system in different modes of its operation. The calculation of the vector payoffs of this game is related to the simulation of the synthesized nonlinear system for different operating modes of the system, input signals and values of the plant parameters. The solutions of this vector game are calculated on the basis of the system of Pareto-optimal solutions, taking into account the binary relations of preferences, on the basis of the stochastic metaheuristic of Archimedes optimization algorithm by several swarms. Thanks to the synthesis of nonlinear robust control with two degrees of freedom by a discrete-continuous object, it is shown that the use of synthesized controllers made it possible to increase the accuracy of control of an electromechanical system with distributed parameters of the mechanical part to reduce the time of transient processes by 1.5–2 times, reduce dispersion of errors by 1.3 times and reduce the sensitivity of the system to changes in the plant parameters in comparison with typical controllers used in existing systems. Further improvement of control accuracy is restrained by energy limitations of executive mechanisms and information limitations of measuring devices.

Optimal fault‐tolerant control for Markov jump power systems with asynchronous actuator faults

AbstractCommunication problems in the sensor‐to‐controller and controller‐to‐actuator channels can cause both the controller and actuator to run asynchronously with the original system in different operating modes. This paper investigates an optimal fault‐tolerant control approach for Markov jump power systems (MJPSs) with asynchronous controller and actuator. Firstly, an asynchronous controller is proposed to deal with incomplete information (i.e., system modes) transmission in the sensor‐to‐controller channel. Secondly, a new asynchronous actuator faults model is constructed to simultaneously represent the two partial losses, of modes information in the controller‐to‐actuator channel, and of control effectiveness (LoCE) caused by actuator faults. Under this framework, two related hidden Markov models (HMMs) are formed, which reveal that both the controller and actuator are asynchronous with the controlled system in different modes. By using Lyapunov and optimal approaches, sufficient conditions are derived to ensure that MJPSs are mean square stable with an optimal guaranteed cost. Finally, Monte Carlo simulations are used to verify the effectiveness of the proposed control method.

Holistic Approach to Ensuring Safety and Cybersecurity in the Use of Intelligent Technologies in Air Transport

The article is devoted to the study and analysis of the problems associated with the use of intelligent technologies in air transport security and cybersecurity issues. Possible dangers that may arise when using autonomous systems, including autonomous aircraft, are considered. The technical measures that can be taken to prevent these dangers, including the development of new methods of cybersecurity and protection against hacker attacks, are analyzed. The problem of ensuring security in air transport associated with the introduction of new technologies and automated systems is investigated. The risks associated with this process are described, such as possible aircraft accidents, data storage problems, and passenger safety issues. Technical measures that can be taken to ensure safety in air transport, including the development of new technologies and diagnostic methods that can detect possible problems before they become serious, are considered. Practical solutions to these problems are proposed, including the development of new security and cybersecurity systems that can be used in air transport. The technical measures that can be taken to ensure the safety and efficiency of the use of intelligent technologies in air transport are described. It is established that the developed simulation model can serve as an effective tool for managing the processes of aircraft ground handling at the airport, as well as allow predicting the results of such processes and developing algorithms for the rational allocation of resources, considering the functioning of the system in different modes. To ensure the efficient functioning of the aircraft ground handling system, it is proposed to implement technical measures to improve cybersecurity and ensure the system's resilience to possible cyberattacks.

Анализ безопасности систем NOMA

Existing Physical Layer Security (PLS) schemes for NOMA are either based on cryptography-based approaches or are limited to approaches that require high processing complexity and key sharing. The conventional NOMA system suffers from security risks and weaknesses, such as being prone to external or internal eavesdropping. By sending NOMA messages to multiple users at the same time on the same resources, there is a risk that an unauthorized user could eavesdrop on or access multiple users' information if the NOMA transmission is successfully intercepted. The NOMA system is susceptible to internal interception when protecting confidential data in cases where untrusted users are present. Therefore, traditional methods of data exchange cannot provide the required level of secrecy for NOMA systems. The results. The work uses non-orthogonal access (NOMA) technology and security assessment of various wireless communication systems using NOMA, such as cognitive radio networks, systems with support for relaying the IoT mode, as well as the D2D mode. The results of the analysis of security characteristics and operation of the NOMA system in different modes are presented.

Passivity-Based Control of Water Pumping System Using BLDC Motor Drive Fed by Solar PV Array with Battery Storage System

In remote locations, it is advisable to combine solar water pumping with electric energy storage and power supply for other forms of consumption. In such complex systems, individual subsystems feature their own local control, and the general automatic control of the system in different modes of its operation is carried out in accordance with an energy management strategy (EMS). In this paper, the functions of local and general control of the solar water pumping system with battery storage and external power supply are combined in the system of passivity-based control (PBC). The EMS is constructed in such a way that for all modes, only two PBC systems are developed, which are switched depending on the battery’s state of charge and the current levels of the two main disturbances—solar irradiation and electrical consumption. For each system, two control influence former (CIF) structures were synthesized and their operation was investigated by computer simulation. Despite the simplicity of CIFs’ implementation, due to the introduced interconnection and damping coefficients, such control allows the provision of the required voltage regulation with a static error up to 1%, sufficient quality of transients during disturbances and switching of the system structure, as well as system asymptotic stability.

Fast-Slow Coupling Dynamics Behavior of the van der Pol-Rayleigh System

In this paper, the dynamic behavior of the van der Pol-Rayleigh system is studied by using the fast–slow analysis method and the transformation phase portrait method. Firstly, the stability and bifurcation behavior of the equilibrium point of the system are analyzed. We find that the system has no fold bifurcation, but has Hopf bifurcation. By calculating the first Lyapunov coefficient, the bifurcation direction and stability of the Hopf bifurcation are obtained. Moreover, the bifurcation diagram of the system with respect to the external excitation is drawn. Then, the fast subsystem is simulated numerically and analyzed with or without external excitation. Finally, the vibration behavior and its generation mechanism of the system in different modes are analyzed. The vibration mode of the system is affected by both the fast and slow varying processes. The mechanisms of different modes of vibration of the system are revealed by the transformation phase portrait method, because the system trajectory will encounter different types of attractors in the fast subsystem.

Electrical Capacitance Volume Tomography (ECVT) for Characterization of Additively Manufactured Lattice Structures (AMLS) in Gas-Liquid Systems

Against the background of current and future global challenges, such as climate change, process engineering requires increasingly specific solutions adapted to the respective problem or application, especially in gas–liquid contact apparatuses. One possibility to adjust the conditions in this kind of apparatuses is an intelligent and customized structuring, which leads to consistent fluid properties and flow characteristics within the reactor. In the course of this, the interfacial area for mass transfer, as well as residence times, have to be adjusted and optimized specifically for the respective application. In order to better understand and advance the research on intelligent customized additively manufactured lattice structures (AMLS), the phase distributions and local gas holdups that are essential for mass transfer are investigated for different structures and flow conditions. For the first time a tomographic measurement technique is used, the Electrical Capacitance Volume Tomography (ECVT), and validated with the volume expansion method and a fiber optical needle probe (A2PS-B-POP) for an air-water system for different modes of operation (with or without co-current liquid flow in empty or packed state). The ECVT proved to be particularly useful for both in the empty tube and the packed state and provided new insights into the phase distributions occurring within structured packings, which would have led to significantly underestimated results based on the visual reference measurements, especially for a densely packed additively manufactured lattice structure (5 mm cubic on the tip). Particularly for the modified structures, which were supposed to show local targeted differences, the ECVT was able to resolve the changes locally. The additional use of a pump for co-current flow operation resulted in slightly higher fluctuations within the ECVT data, although local events could still be resolved sufficiently. The final comparison of the empty tube at rest data with a fiber optical needle probe showed that the results were in good agreement and that the local deviations were due to general differences in the respective measurement techniques.

Моделювання оцiнки рiвня ризику функцiонування соцiо-економiчних систем

The research of the actual task of developing the technology of assessing the level of functioning of the system to support decision making from the regular mode to the disaster.For the first time, the study presents inputs for assessing the functioning of the system in a hybrid manner, based on the experience, knowledge and expertise of experts, as well as data mining. A block diagram of the assessment of the level of functioning of the system to support decision making is demonstrated.For the first time, a fuzzy mathematical model for evaluating the level of functioning of a system to support decision-making is proposed, according to a step-by-step algorithm based on expert hybrid data, using linguistic and quantitative variables. In doing so, the criterion estimates of the functioning system are aggregated based on the decision maker’s judgment (pessimistic / cautious / average / optimistic scenarios). According to the threshold of possibility of functioning of system there is a risk assessment for quality ofdecision-making in different modes. As a result of evaluating the system in different modes of operation, we obtain a quantitative assessment of the risk of system functioning relative to the scenario of the event deployment, the linguistic level of system functioning and the level of risk acceptance of the system functioning. All this allows to reveal uncertainties of expert opinions and data obtained, substantiate the degree of decision-making and draw adequate conclusions, taking into account the mode of operation of the system.Within the framework of the developed research, a logical statement of the rule of belonging of linguistic assessments, matrix and knowledge base of determining the acceptability of the level of risk of functioning of the system is formulated.The validity of the obtained results is ensured by the correct use of intellectual knowledge analysis, systematic approach, fuzzy set theory and fuzzy logic, which is confirmed by the research results. The research conducted will be a useful tool to support decisionmaking, to create and manage decisions in different modes of system operation.

Solar PV based nanogrid integrated with battery energy storage to supply hybrid residential loads using single‐stage hybrid converter

This study proposes a solar photovoltaic (PV) based nanogrid with integration of battery energy storage to supply both AC and DC loads using single-stage hybrid converter. A boost derived hybrid converter (BDHC) is used as a single-stage converter to supply the AC/DC hybrid loads. The BDHC reduces the number of conversion stages when compared to the conventional solar PV based systems to supply the AC/DC loads. A non-isolated buck–boost bidirectional DC–DC converter is used for charging and discharging of the battery to support the nanogrid. The power reference algorithm proposed in this study provides the proper utilisation of the solar PV in different operating conditions and uninterruptable power supply to the loads along with the battery storage management. A modulation scheme is implemented to operate the BDHC for generation of AC/DC hybrid outputs from a single input. The performance of the proposed system in different modes of operation has been evaluated using PSCAD simulation studies. A laboratory experimental setup is developed and control algorithms are implemented using LabVIEW based FPGA controller for verification of the results.

Contribution management of lead‐acid battery, Li‐ion battery, and supercapacitor to handle different functions in EVs

One of the most concerning issues regarding electrical vehicles (EVs) is limited driving cycle and protracted charging process. In order to improve the efficiency of current batteries, appropriate energy management systems (EMSs) could be deployed to compensate these defects. To overcome these obstacles, an EMS including a bidirectional Cuk converter and a battery storage with two types of batteries is proposed. Lithium-ion (Li-ion) and lead-acid battery types are considered as the main battery and auxiliary battery packs, respectively. Moreover, a supercapacitor is utilized to help the auxiliary battery for handling fast dynamics of the power delivery in braking and acceleration conditions. While the function of the main battery is to be charged and discharged in normal conditions, handling harsh conditions lies upon the auxiliary battery. So, the auxiliary battery can be rapidly discharged during acceleration and quickly recharged in charge stations. Furthermore, it can be used for an exchangeable battery strategy aimed at reducing congestion at charge stations. In order to plan for different scenarios, a Cuk converter is employed as a convenient interface between the batteries to manage power sharing. Operation of the system in different modes are discussed comprehensively. The performance of the proposed topology is assessed using some simulations and experiments in different conditions.

Http://izvuzmash.ru/catalog/avroc/airc/1649.html

Hydrodynamic analysis with the aid of numerical modeling tools is widely used in the design and modernization of hydraulic systems of aircraft, as well as in the analysis of the causes of depressurization, local destruction, and so on. This analysis includes both the operation of the hydraulic system in different modes, and the process of switching from one mode to another. However, in the scientific literature there is no information that would take account of high-frequency pressure pulsations from the hydraulic pump in the dead-end lines of hydraulic systems, and their possible impact on the pipelines and attachment points to the elements of the airframe. In the scope of this research, the possibility of low-frequency resonance in the dead-end lines of hydraulic systems is determined. A technique for setting and performing finite-volume modeling and hydro-gasdynamic analysis is described. The results of the analysis of the eigenfrequencies of oscillations in prefabricated structures of the hydraulic system pressure lines are presented. It is proven that the frequency of the resulting low-frequency resonance of the hydraulic fluid pulsations does not correspond to any of the eigenfrequencies of oscillations of the structural elements, and is, therefore, forced. The need for further assessment of the degree of influence of the described phenomenon on the operational life of the attachment points to the elements of the airframe is highlighted.

Features of Estimation of Structural Reliability of Power Supply Systems

Development and operation of modern power supply systems of consumers which are the part of distributed generation (DG) systems with their communication with electric power system (EPS) and renewable energy sources (RES) demand changes in estimation of their reliability indicators on the basis of corresponding mathematical apparatus. It is shown that DG systems refer to structures with several overlapping zones of action, which determines their peculiarities, which are represented by some integral characteristic - efficiency of operation, which characterizes the degree of expediency of use of the DG system in different modes. The approach based on evaluation of effectiveness of such systems is offered. Examples of calculation of relatively simple structures of DG systems performing several tasks simultaneously are given.

Remote Supervision and Control of Air Conditioning Systems in Different Modes

In the era of automation, most of the application of engineering and science are interrelated with system for optimal operation. To get the efficient result of an operation and desired response, interconnected systems should be controlled by directing, regulating and commanding. Here, air conditioning (AC) system is considered for experimentation, to supervise and control its functioning in both, automated and manual mode. This paper reports the work intended to design and develop an automated and manual AC system working in remote and local mode, to increase the level of comfort, easy operation, reducing human intervention and faults occurring in the system. The Programmable Logical Controller (PLC) and Supervisory Control and Data Acquisition (SCADA) system were used for remote supervision and monitoring of AC systems using series ninety protocol and remote terminal unit modbus protocol as communication module to operate in remote mode. PLC was used as remote terminal for continuous supervision and control of AC system. SCADA software was used as a tool for designing user friendly graphical user interface. The proposed SCADA AC system successfully monitors and controls in accordance within the parameter limits like temperature, pressure, humidity and voltage. With all the features, this designed system is capable of efficient handling of the resources like the compressor, humidifier etc., with all the levels of safety and durability. This system also maintains the temperature and controls the humidity of the remote location and also looks after the health of the compressor.

THE ROLE OF MOTION MONITORING IN EXPERIMENTS ON SLIDING FRICTION IN FLAT-ON-FLAT METALLIC CONTACTS

The paper describes an example of an experiment on sliding friction of metallic materials in which vibration measurement methods were used to identify friction induced vibrations occurring in sliding. The determination of the parameters of the motion of the critical components in the sliding system in different modes of operation allowed using the vibration signal as a source of information pertaining to the observed process. The tests performed with a metallic material were inspired by the earlier research performed with machine ceramics in which the result of vibration analysis allowed the determination of the correctness of measurement with regard to the conditions of contact and the analyses of the nature of the observed effect of vibration on the inflicted friction. The motion analysis data was used as a basis for a screening method eliminating corrupted measurements from the data set used for global evaluation of the friction characteristics. It was confirmed that, in a steel-on-steel sliding system, similar friction and vibration regimes occur as in ceramics-on-ceramics, but the effects of certain vibration modes are opposite in the two systems, despite the same load/velocity conditions.

Parameter analysis of thermoelectric generator/dc-dc converter system with maximum power point tracking

The power generated from TEG is relatively unstable owing to temperature variations at its hot and cold side terminals. The dc-dc converters can provide more stable power output thereby improving the overall efficiency of TEG system. However, to facilitate better performance improvement, maximum power point tracking (MPPT) algorithm can be applied to extract maximum power from TEG system. Therefore, parameter analysis of a TEG/dc-dc converter system in different modes is being carried out. A TEG-dc-dc boost converter model is analysed in both MPPT and direct pulse width modulation (PWM) modes subjected to a variable load. To further study the capability of dc-dc converters to stabilise the TEG power output, increasing ramp and random hot side temperature is applied to the MPPT and direct PWM based modes so that the effect on output parameters i.e. voltage and power, can be analysed. It is noted that even for the random temperature input to the TEG, the output voltage resulting from the converter is almost constant. Therefore dc-dc converters are able to stabilise the power generated from TEG. It is also observed that dc-dc converter with MPPT based model is able to effectively extract the maximum power without having to adjust any component from the MPPT algorithm as it is the case with direct PWM based model. From the study, it has been established that proper selection of converter components is necessary to reduce converter losses as well interferences on the load connected to TEG-dc-dc converter system.

PARETO OPTIMAL SOLUTION OF MULTIOBJECTIVE SYNTHESIS OF ROBUST CONTROLLERS OF MULTIMASS ELECTROMECHANICAL SYSTEMS BASED ON MULTISWARM STOCHASTIC MULTIAGENT OPTIMIZATION

Purpose. Developed the method for solving the problem of multiobjective synthesis of robust control by multimass electromechanical systems based on the construction of the Pareto optimal solutions using multiswarm stochastic multi-agent optimization of particles swarm, which reduces the time of determining the parameters of robust controls multimass electromechanical systems and satisfy a variety of requirements that apply to the work of such systems in different modes. Methodology. Multiobjective synthesis of robust control of multimass electromechanical systems is reduced to the solution of solving the problem of multiobjective optimization. To correct the above problem solving multiobjective optimization in addition to the vector optimization criteria and constraints must also be aware of the binary preference relations of local solutions against each other. The basis for such a formal approach is to build areas of Pareto-optimal solutions. This approach can significantly narrow down the range of possible solutions of the problem of optimal initial multiobjective optimization and, consequently, reduce the complexity of the person making the decision on the selection of a single version of the optimal solution. Results . The results of the synthesis of multi-criteria electromechanical servo system and a comparison of dynamic characteristics, and it is shown that the use of synthesized robust controllers reduced the error guidance working mechanism and reduced the system sensitivity to changes in the control parameters of the object compared to the existing system with standard controls. Originality. For the first time, based on the construction of the Pareto optimal solutions using a multiswarm stochastic multi-agent optimization particle algorithms improved method for solving formulated multiobjective multiextremal nonlinear programming problem with constraints, to which the problem of multiobjective synthesis of robust controls by multimass electromechanical systems that can significantly reduce the time to solve problems and meet a variety of requirements that apply to the multimass electromechanical systems in different modes. Practical value. Practical recommendations on reasonable selection of the target vector of robust control by multimass electromechanical systems. Results of synthesis of electromechanical servo system shown that the use of synthesized robust controllers reduced the error guidance of working mechanism and reduce the system sensitivity to changes of plant parameters compared to a system with standard controls.

Архітектура та функціональні можливості мультиагентної системи Навігація

The features of the design, development and functioning of the multi-agent system Navigation are investigated. System architecture and substantiate the choice of language implementation of the system are provided. The functionality of the subsystems of multi-agent systems Navigation is analyzed in detail. The results of multi-agent modelling of pursuit/escape processes by means of the multi-agent system in different modes of its functioning are compared on meaningful example.