Operation Of Supply Networks Research Articles

ПРИМЕНЕНИЕ ПОВЫСИТЕЛЬНЫХ НАСОСНЫХ СТАНЦИЙ ДЛЯ МОДЕРНИЗАЦИИ СИСТЕМ ТЕПЛОСНАБЖЕНИЯ

The authors consider the problem of insufficient power of existing boiler houses and heat supply networks in large cities, which leads to overloads and accidents. Modernization of operation in heat supply system is aimed at improving energy efficiency, environmental safety and reliability of heat supply networks. The use of modern technologies provides a significant improvement in the operation of heat supply systems and makes the coolant more accessible and efficient for consumers. To ensure uninterrupted operation of heat supply facilities in residential areas and efficient operation of heat supply networks and heating mains in hard-to-reach areas with difficult terrain, the authors proposed to install or modernize booster pumping stations. Such stations help to keep the required parameters of the coolant and to provide heat consumers with quality coolant. The article discusses the operating principle of pumping stations and provides a functional diagram of process automation. Piezometric diagrams of preand post-installation of booster pumping stations allow us to speak about the positive effect of booster pumping stations modernization in the heat supply system. Thus, after reconstruction, the total capacity of pumping groups on the direct and return circuits increased by 1.33 times, the head in the system – by 1.12 times.

Overvoltages at the incomplete phase modes of transformer operation in the networks of mining enterprises and methods of their limitation

The article presents analytical and graph-analytical methods of calculating overvoltages under incomplete-phase modes of power transformer operation with verification of their adequacy on mathematical models in Matlab Simulink software package. The existing solutions were analyzed for their efficiency in relation to mine networks. The overvolt-age levels at breakages in the most probable points of distribution network of one of the own open-pit mines of metal-lurgical enterprise have been determined. The circuit solutions for reducing the overvoltages on power transformers with different winding connection groups in incomplete phase modes of supply network operation have been developed and their mathematical models have been constructed. By means of Simulink package a number of calculations for deter-mining the necessary parameters of the proposed schemes of overvoltage limitation with graphical representation of the results have been made. Attention is paid to the unification of the study results for a wider and more flexible applica-tion.

Cluster Analysis to Identify Priority Areas for Water Quality Management in Water Supply Systems

Zoning methodologies, such as district metered areas (DMA), are commonly employed to robustly maintain water pipe network systems in both normal and abnormal situations. However, the management and evaluation typically associated with existing DMAs primarily focus on ensuring stable water volume and pressure. Consequently, these methods do not adequately address the maintenance of water quality elements within the water supply system, such as adequately managing residual chlorine and reducing water quality complaints. This study introduced a zoning tailored explicitly for managing water quality-oriented elements, facilitating stable water quality management, and enhancing responses to water quality incidents in large-scale domestic water supply networks. A method was proposed to establish priorities for each zone, using various geographic information system (GIS)-based water quality-related structured data (such as water quality measurement data and pipe data) and unstructured data (such as water quality complaints). Comprehensive water quality management was achieved by applying machine learning techniques based on clustering analysis to derive evaluation factors. The proposed methodology was implemented in Metropolitan City A in Korea, leading to the derivation and analysis of evaluation results. This data-centric water supply network priority management area designation methodology, as presented in this study, is anticipated to serve as a valuable decision-making tool for enhancing the accuracy and reliability of water supply network operation and the overall management of water supply operators.

Critical risks in global supply networks: A static structure and dynamic propagation perspective

The global fragmentation of supply networks results from outsourcing and offshoring strategies. Supply networks outsource segments to specialized suppliers, thereby leveraging their enhanced adaptability and reduced costs. These practices have produced intricate interdependence patterns, facilitating the spread of disruption risk. Although risk management provides extensive toolsets for addressing critical risks at the dyadic level, there has been a lack of emphasis on evaluating the efficacy of these tools in the context of complex global supply networks. Research generally concentrates on the topological properties of global supply networks while largely ignoring the underlying risk propagation process in identifying critical risks. This paper develops a comprehensive view of the supply network through detailed subtier mapping and a mathematical formulation that overcomes the limitations of the current approaches. The proposed formulation model incorporates the doing business environment of each country and reproduces the spread of disruption risks under three disruption risk scenarios in global supply networks. This paper illustrates the proposed formulation by analyzing the critical risks of global flat panel display supply networks. The results suggest that these networks are robust to random disruption but susceptible to target disruptions. Additionally, disruptions in European and Asian countries have detrimental effects on the overall operation of supply networks.

Focus on Monitoring and Control of Complex Supply Systems

Abstract The ongoing rapid transformation of our energy supply challenges the operation and stability of electric power grids and other supply networks. This focus issue comprises new ideas and concepts in the monitoring and control of complex networks to address these challenges.

Water distribution network expansion: an evaluation from the perspective of complex networks and hydraulic criteria

Abstract The expansion of water distribution networks is nowadays essential to meet the pressing population growth in many cities worldwide. With the subsequent increase in water demand, the hydraulic behaviour of a water supply system can change dramatically due to the significant head losses in the pipes caused by the larger flows released by pumping systems and reservoirs to supply the higher water consumption of the network. Strategical studies are necessary to delimit risk regions where a demand increase may affect the system too negatively. To analyse expansion scenarios with the lowest risk of failure and damage for the supply network operations, this research studies hydraulic performance and connectivity under various demand increase scenarios using calculations of complex network metrics together with relevant hydraulic criteria. For these calculations, this research, developed in Python, uses, respectively, the NetworkX 2.5 and WNTR 0.3.0 packages. The C-Town network is employed as a case study, and demand increasing scenarios are implemented on 30 nodes along the peripheral regions of the network to simulate the growth of the cities. Then, these scenarios are evaluated using the TOPSIS methodology, thus determining the best and worst sectors to expand the capacity of the network.

Spectroscopy of the interaction of cosmic plasma flows with the Earth's atmospheric aerosols

The article deals with questions about the interaction of solar plasma flows with atmospheric gas containing CDP molecules and particles. Modeling and calculations of existing electric currents and their structure were carried out. Conclusions are drawn about the effect on the structure of the current both from the side of the atmosphere and from cosmic streams of different composition. The equation of motion of a plasma with a condensed dispersed phase (CDP) in the Earth's ionosphere is considered. Conclusions are drawn about the effect of CDP on the thermal balance of plasma. It has been found that in rarefied layers of the ionosphere, plasma flows mixed with CDP are subjected to significant additional heating from CDP particles, and the lower ones serve as a heat-removing agent. Attention is drawn to the most important aspects of the results obtained in the context of their impact on the operation of power supply networks during strong solar flares. Taking into account the nature of the explosive processes that form the plasma flows from which the electric current is formed, the fluctuations of the currents inside the magnetic tubes are determined. The possible influence of these factors on the operation of the power grid line in the mountains, around the polar and equatorial zones is also considered. Such influence depends on the amplitude fluctuations of the physical parameters of the medium that forms the atmospheric currents.

Numerical modeling and rational methods of water supply network operations in environmental engineering systems

This research paper uses a numerical modeling process to recreate the actual operating conditions of the water distribution system in the town of Kleosin, located on the border with Bialystok. The performed calculations allowed for the creation of a model for the functioning of the water supply network and for taking rational and optimal decisions affecting the effective operation of the entire system. The numerical modeling process is presented as a common tool to rationally and optimally manage the water distribution system. At the same time, numerous possibilities of computationally modeling and processing accurate real data were presented. The scope of the study included the network model analyzed in terms of the basic quality parameters that the network should meet, such as flow velocity, pressure, unit losses, water age, and operating conditions during simulated events, such as expansion or system failure, broken down into assumed time variants. As part of the paper, a situational variant was presented, which concerned the planned modernization in order to improve the functioning of the system by extending water distribution with new sections. The Epanet computer program distributed by US EPA was used in the research.

Additive manufacturing integration in E-commerce supply chain network to improve resilience and competitiveness

In light of recently increased e-commerce, also a result of the COVID-19 pandemic, this study examines how additive manufacturing (AM) can contribute to e-commerce supply chain network resilience, profitability and competitiveness. With the recent competitive supply chain challenges, companies aim to decrease cost performance metrics and increase responsiveness. In this work, we aim to establish utilisation policies for AM in a supply chain network so that companies can simultaneously improve their total network cost and response time performance metrics. We propose three different utilisation policies, i.e. reactive, proactive – both with 3D printing support – and a policy excluding AM usage in the system. A simulation optimisation process for 136 experiments under various input design factors for an (s, S) inventory control policy is carried out. We also completed a statistical analysis to identify significant factors (i.e. AM, holding cost, lead time, response time, demand amount, etc.) affecting the performance of the studied retailer supply chain. Results show that utilising AM in such a network can prove beneficial, and where the reactive policy contributes significantly to the network performance metrics. Practically, this work has important managerial implications in defining the most appropriate policies to achieve optimisation of supply network operations and resilience with the aid of AM, especially in times of turbulence and uncertainty.

Модель совместной работы системы тягового и внешнего электроснабжения

Purpose: To improve record accuracy of external power supply network influence on the operation of traction power supply systems of industrial frequency AC. The article shows that existing mathematical models of traction and external power supply joint operation have sounding limitations. These limitations almost exclude the possibility of their practical use. At the same time, when projecting a new electrification, it is required to choose the most efficient external power supply scheme. At the exploitation of existing electrified sections, the necessity arises to assess equalizing current value during repairs in external power supply networks and to adopt a decision on changing power supply and sectioning schemes. Corresponding model is required to solve these tasks. Methods: Analysis of existing mathematical models and computer programs for joint calculation for traction and external power supply networks. Development of three-phase PU-generator models on the basis of EMF source behind an inductive resistance, development of three-phase and single-phase load models. Results: The article presents a description of a mathematical model implied to study the joint operation of 25 kV AC traction power supply systems and 110-750 kV power supply systems. The principles of building the model of three-phase and single-phase PU-generators on EMF source basis behind inductive resistance as well as the models of three-phase and single-phase loads are considered. Based on the given mathematical expressions, a computer model has been developed that allows analyzing the joint operation of three-phase external power supply networks and single-phase traction ones. The model is implemented in MATLAB-Simulink software package. Using this computer model, the influence of power flows through 110–330 kV network of Karelenergo and “FSK EAS” Public Companies on equalizing currents in the traction network of Knyazhaya — Idel section of Oktyabrskaya railway was analyzed. Practical importance: The reliability raise for traction power supply system operation at the expense of precise calculation of equalizing currents. Energy loss reduction in a traction network in account of traction network optimal power supply scheme choice.

Combined Control System for the Coordinates of the Electric Mode in the Electrotechnological Complex “Arc Steel Furnace-Power-Supply Network”

To stabilize the electrical mode of an arc steelmaking furnace in the initial stages of melting, it is advisable to use a high-speed current-limiting system, in addition to the traditional electrode movement control system. This system is implemented by including the primary winding of the furnace transformer choke, controlled by thyristors. The use of such a system, on the one hand, reduces the negative impact of the arc steel furnace on the the power supply network operation and, on the other, affects the operation of the electrode movement system, built on the principle of an impedance regulator. In order to analyze the mutual influences between such systems, a mathematical model for the power supply and control system of the arc steelmaking furnace was created. The developed model can work in real time, which corresponds to the world trends of modern control system synthesis for complex technological objects. In the created model, the work of the combined control system with different approaches to the formation of the control effect in the high-speed circuit and the effect of the combined control system on the power supply system of the ASF are analyzed.

Risk Assessment of Water Supply Network Operation Based on ANP-Fuzzy Comprehensive Evaluation Method

AbstractThe water supply network is of great importance for a city, and it faces various risks such as leaks and breaks, so its risk level needs to be evaluated regularly. To propose a new and effi...

Comparative Analysis of Illicit Supply Network Structure and Operations: Cocaine, Wildlife, and Sand

Illicit supply networks (ISNs) are composed of coordinated human actors that source, transit, and distribute illicitly traded goods to consumers, while also creating widespread social and environmental harms. Despite growing documentation of ISNs and their impacts, efforts to understand and disrupt ISNs remain insufficient due to the persistent lack of knowledge connecting a given ISN’s modus operandi and its patterns of activity in space and time. The core challenge is that the data and knowledge needed to integrate it remain fragmented and/or compartmentalized across disciplines, research groups, and agencies tasked with understanding or monitoring one or a few specific ISNs. One path forward is to conduct comparative analyses of multiple diverse ISNs. We present and apply a conceptual framework for linking ISN modus operandi to spatial-temporal dynamics and patterns of activity. We demonstrate this through a comparative analysis of three ISNs – cocaine, illegally traded wildlife, and illegally mined sand – which range from well-established to emergent, global to domestic in geographic scope, and fully illicit to de facto legal. The proposed framework revealed consistent traits related to geographic price structure, value capture at different supply chain stages, and key differences among ISN structure and operation related to commodity characteristics and their relative illicitness. Despite the diversity of commodities and ISN attributes compared, social and environmental harms inflicted by the illicit activity consistently become more widespread with increasing law enforcement disruption. Drawing on these lessons from diverse ISNs, which varied in their histories and current sophistication, possible changes in the structure and function of nascent and/or low salience ISNs may be anticipated if future conditions or law enforcement pressure change.

Computer-aided Construction of Big Data Mining Platform in Subway Power Supply Network Operation Monitoring

Computer-Aided Design and Applications is an international journal on the applications of CAD and CAM. It publishes papers in the general domain of CAD plus in emerging fields like bio-CAD, nano-CAD, soft-CAD, garment-CAD, PLM, PDM, CAD data mining, CAD and the internet, CAD education, genetic algorithms and CAD engines. The journal is aimed at all developers and users of CAD technology to ptovide CAD solutions for various stages of design and manufacturing. The journal publishes all about Computer-Aided Design and Computer-Aided technologies.

A Comparative Analysis of Machine Learning Approaches for Short-/Long-Term Electricity Load Forecasting in Cyprus

Estimating the electricity load is a crucial task in the planning of power generation systems and the efficient operation and sustainable growth of modern electricity supply networks. Especially with the advent of smart grids, the need for fairly precise and highly reliable estimation of electricity load is greater than ever. It is a challenging task to estimate the electricity load with high precision. Many energy demand management methods are used to estimate future energy demands correctly. Machine learning methods are well adapted to the nature of the electrical load, as they can model complicated nonlinear connections through a learning process containing historical data patterns. Many scientists have used machine learning (ML) to anticipate failure before it occurs as well as predict the outcome. ML is an artificial intelligence (AI) subdomain that involves studying and developing mathematical algorithms to understand data or obtain data directly without relying on a prearranged model algorithm. ML is applied in all industries. In this paper, machine learning strategies including artificial neural network (ANN), multiple linear regression (MLR), adaptive neuro-fuzzy inference system (ANFIS), and support vector machine (SVM) were used to estimate electricity demand and propose criteria for power generation in Cyprus. The simulations were adapted to real historical data explaining the electricity usage in 2016 and 2107 with long-term and short-term analysis. It was observed that electricity load is a result of temperature, humidity, solar irradiation, population, gross national income (GNI) per capita, and the electricity price per kilowatt-hour, which provide input parameters for the ML algorithms. Using electricity load data from Cyprus, the performance of the ML algorithms was thoroughly evaluated. The results of long-term and short-term studies show that SVM and ANN are comparatively superior to other ML methods, providing more reliable and precise outcomes in terms of fewer estimation errors for Cyprus’s time series forecasting criteria for power generation.

Collective effects of link failures in linear flow networks

The reliable operation of supply networks is crucial for the proper functioning of many systems, ranging from biological organisms such as the human blood transport system or plant leaves to man-made systems such as power grids or gas pipelines. Whereas the failure of single transportation links has been analysed thoroughly, the understanding of multiple failures is becoming increasingly important to prevent large scale damages. In this publication, we examine the collective nature of the simultaneous failure of several transportation links. In particular, we focus on the difference between single link failures and the collective failure of several links. We demonstrate that collective effects can amplify or attenuate the impacts of multiple link failures—and even lead to a reversal of flows on certain links. A simple classifier is introduced to predict the overall strength of collective effects that we demonstrate to be generally stronger if the failing links are close to each other. Finally, we establish an analogy between link failures in supply networks and dipole fields in discrete electrostatics by showing that multiple failures may be treated as superpositions of multiple electrical dipoles for lattice-like networks. Our results show that the simultaneous failure of multiple links may lead to unexpected effects that cannot be easily described using the theoretical framework for single link failures.

STUDY OF 50 HZ ELECTROMAGNETIC FIELDS IN RESIDENTIAL AREAS AND EXPERT ASSESSMENT OF THE POPULATION HEALTH STATUS

Introduction. The real electromagnetic situation in a residential area in the process of power supply network operation and health status assessment of population living in the vicinity of overhead transmission lines (OTL) of various voltages and transformer substations (TS) are of current interest. The effect of 50 Hz electric fields (EF) and magnetic fields (MF) on human health has not been sufficiently studied. Material and Methods. Measurement and assessment of 50 Hz EF and MF levels generated by 35, 110 and 220 kV OTL and by 6 kinds of closed-type transformer substations were carried out. Chronic overstrain index was used to assess population health status. Questionnaire study data among residents in the vicinity of 110-220 kV OTL were used for calculation of chronic overstrain index. Results. Closed-type transformer plants don’t generate EMF or exceed 50 Hz EF or MF health standards (HS). Electric field intensity levels exceeding HS were registered under 110 and 220 kV OTL. EMF health standards were not exceeded at a distance of 2 m from 110 kV OTL and 10 m from 220 kV OTL. Magnetic field induction levels did not exceed maximum allowable levels. Significant levels of chronic overstrain were revealed in residents living at a distance of under 300 m from 110-220 kV OTL. Conclusions. Closed-type transformer substations do not generate 50-Hz EMF exceeding health standards. Compliance with the electrical safety requirements of overhead transmission lines (overhead line safety zones) provides compliance with the maximum allowable levels of 50 Hz electric and magnetic fields. Population health risk assessment study among the population in the vicinity of OTL is relevant.

Hybrid Technologies for Creating Energy Accumulation Systems

The article discusses the research and development of the electric power storage devices based on hybrid technologies. Studies and analysis of the required conditions for the application of energy storage systems have shown that their main technical characteristics - stored energy, output power and discharge time obviously cannot be implemented in at least scalable but identical technical devices. In order to solve this problem, the hybrid technologies and he differentiation of energy storage systems are used according to the conditions of applying. For example, to ensure the quality of power supply of almost all end-users of the industrial and private sector, it has been proposed to use hybrid accumulation systems based on batteries and supercapacitors. Hybrid power storage systems of this type have identical technical solutions with an operating voltage of 380 volts and a nominal power in the range of units of kilowatts - units of megawatts depending on the power of the storage elements used. The article shows that ensuring the quality of power supply to consumers of electricity in petrochemical industries subject to emergency shutdowns and significant violations of regulatory requirements for the quality of power supply due to incorrect operation of power supply networks and other high-voltage equipment is possible with the help of hybrid energy storage systems of the kilovolt and megawatt ranges based on batteries of supercapacitors and static compensators of reactive power which allow supporting a required level and quality of the voltage, increase the capacity of transmission lines.

Intelligent autonomous vehicles in digital supply chains

PurposeThe purpose of this paper is twofold: first, to discuss key challenges associated with the use of either simulation or real-world application of intelligent autonomous vehicles (IAVs) in supply network operations; and second, to provide a theoretical and empirical evidence-based methodological framework that supports the integrated application of conceptualisation, simulation, emulation and physical application of IAVs for the effective design of digital supply networks.Design/methodology/approachFirst, this study performs a critical review of the extant literature to identify major benefits and shortcomings related to the use of either simulation modelling or real-word application of physical IAVs. Second, commercial and bespoke software applications, along with a three-dimensional validation and verification emulation tool, are developed to evaluate an IAV’s operations in a conceptual warehouse. Third, a commercial depth-sensor is used as a test bed in a physical setting.FindingsThe results demonstrate that conceptual and simulation modelling should be initially used to explore alternative supply chain operations in terms of ideal performance while emulation tools and real-world IAV test beds are eminent in validating preferred digital supply chain design options.Research limitations/implicationsThe provided analysis framework was developed using literature evidence along with experimental work and research experience, without consulting any industry experts. In addition, this study was developed based on the application of a single physical device application as a test bed and, thus, the authors should further progress with the testing of a physical IAV in an industrial warehouse.Practical implicationsThe study provides bespoke simulation modelling and emulation tools that can be useful for supply chain practitioners in effectively designing network operations.Originality/valueThis work contributes in the operations management field by providing both a multi-stage methodological framework and a practical “toolbox” for the proactive assessment and incorporation of IAVs in supply network operations.

Humanitarian supply chain management responding to refugees: a literature review

PurposeThe purpose of this paper is to map and analyse the literature from 1989 to 2016 on humanitarian supply chain management (SCM) responding to refugees. This literature review systematically assesses existing literature, thereby highlighting gaps, challenges and directions for future research.Design/methodology/approachThe authors apply a structured content analysis method which has been recognised as a traceable, systematic and reproducible research tool to analyse qualitative and quantitative aspects of existing literature.FindingsThe relative scarcity of literature implies that the interface of the fields of Humanitarian SCM and refugees has been rarely addressed. More specifically, the quantitative content analysis highlights a dearth of research that focusses on both fields in a well-balanced manner. In particular, empirical, practice-led studies, as well as research on development aid operations are under-represented. The qualitative analysis finds that further research on logistics models as well as technological innovations is necessary to increase data availability, forecast accuracy and the efficiency of (local) supply network operations during disasters.Research limitations/implicationsThe review suggests a number of areas in need of future research, proposes possibilities of collaborations between different actors and provides a research agenda for Humanitarian SCM in the context of refugees.Originality/valueThis review is the first to analyse the literature on Humanitarian SCM related to refugees.