Electric Facilities Research Articles

Charging Station Planning of Electric Vehicle in Battery Swapping Scene

In response to the national green development concept, the electric vehicles quantity continues to surge. However, the cost of electric vehicle charging facilities is hindering the development of electric vehicles. Considering charging facility cost and fuel consumption cost of logistics vehicles, we propose the charging planning for electric vehicle batteries. First, according to the user’s mileage, we simulate the maximum demand for electric vehicle batteries in each time. Then, based on the electric vehicle battery charging planning, we establish an optimization model for the number of battery charging equipment and the fuel consumption cost of logistics vehicles. Finally, through specific examples we show the optimal number of delivery is 4 from the battery charging station to the battery swapping station. The battery charging equipment are 368 units and the fuel consumption cost of the logistics vehicle is 8040 RMB per day. In addition, the number of logistics vehicle departures is reduced by 3 compared to the same amount of delivery, which significantly improves the stability and efficiency of the battery swapping scene.

NEURAL NETWORK MODELING OF RELAY PROTECTION WITH A TIME DELAY

Modern electric power facilities – stations and high-voltage substations – have become digital objects with the active use of high-speed local networks directly involved in the technological process. Management, analysis and control of information exchange in the digital substation of the power system require the development of new means and approaches. For these purposes, machine learning methods can be used, in particular the apparatus of artificial neural networks (ANN). The paper shows the possibilities of using direct propagation ANNs (multilayer perceptrons) for modeling and identifying anomalies in the operation modes of relay protection with a time delay. The results of training and testing of the ANN are presented on the example of analyzing the operation of the over current protection in the “sliding time window” mode in a three-phase electrical network. The proposed neuroalgorithm and configuration of the ANN can be used to control the modes and accuracy of relay and cybernetic defenses.

Statistical Characterization of the Magnetic Field in Space during Magnetic Storms

Magnetic storms are an important type of space weather and are usually caused by large streams of charged elementary particles (ions, for example) generated during solar wind production. The occurrence of magnetic storms can pose a threat to the internal electronics of satellites, communication, navigation, remote sensing, etc. Additionally, ground-based electrical facilities may be impacted. In this paper, we focus on the statistical characteristics of the space channel during the occurrence of magnetic storms. By analyzing the observed data for each component of the magnetic field during a magnetic storm and applying the relevant cognitive radio theory, we obtain the probability density function, autocorrelation function, and power spectrum of the magnitude of each component of the magnetic field. The results show that the probability density of the magnitude of each component of the magnetic field gradually deviates from the Gaussian distribution as the Magnetic storm ring current index (Dst index) increases during a magnetic storm, and the autocorrelation function exhibits nonstationary characteristics, which further leads to the time-varying characteristics of the power spectrum.

Research on multi-objective planning of electric vehicle charging stations considering the condition of urban traffic network

As an important supporting facility for electric vehicles, the reasonable planning and layout of charging stations are of great significance to the development of electric vehicles. However, the planning and layout of charging stations is affected by various complex factors such as policy economy, charging demand, user charging comfort, and road traffic conditions. How to weigh various factors to construct a reasonable model of charging station location and capacity has become a major difficulty in the field of electric vehicle charging facility planning. Firstly, this paper constructs the location and capacity optimization model of the charging station with the goal of maximizing the revenue of operators and minimizing the user’s charging additional cost. At the same time, the road time-consuming index is introduced to quantify the impact of road congestion on the user’s charging additional cost, so as to effectively improve the user’s satisfaction during charging. Then, aiming at the charging station planning model, a non-dominated sorting genetic algorithm with an elite strategy (NSGA-II) based on chaos initialization and arithmetic crossover operator is proposed. Finally, taking the Haidian District of Beijing as the simulation object, the results show that compared with the situation of urban traffic networks not considered, the model proposed in this paper significantly reduces the cost of lost time of users by 11.4% and the total additional cost of users’ charging by 7.6%. It not only ensures the economy of the system, but also effectively improves the charging satisfaction of users, which further verifies the feasibility and effectiveness of the model, and can provide a reference for the planning and layout of charging stations in the future.

ELECTRIC RAILWAY POWER CONSUMPTION

The electric railways is a specific consumer of the electric power system. For the purpose of using electric energy rationally and making adequate savings, efforts are made to optimize electric energy consumption of electric trains and other electric railway facilities. The work shows the train movement simulation algorithm which serves to determine primarily the mechanical and then also the electric power required for traction. The sections of the electrified tracks are supplied from the electric traction substation (TS) and, for the requirements of the electric traction calculation, an electric network is formed. Based on the maximum time table for a certain time period, calculation is done of the electric circumstances; electricity, voltage, electric power, as well as the total consumed electric energy. For the determination of the electric energy supply of the traction unit, movement resistances of the certain train on each section need to be calculated. Input data necessary for such a calculation are the tracks profile parameters, planned movement speeds on certain sections, and the properties of the train and the locomotive. Besides the train movement simulation model, the article also shows the analysis of impact factors on the electric energy consumption for the electromotor train which travels the Croatian suburban rails. The results are obtained by the train movement simulation algorithm, by virtue of which the locations of trains are calculated, as well as their mechanical and electric powers necessary for traction. The particular example of the supply of the existing SS serves for comparing the results obtained by electric traction calculation and measurement. Some of the results are given of the electric traction simulation for the Zaprešić SS at the supply of the suburban Podsused factory − Samobor − Bregana which is planned for construction.

PROTECTION DEVICES AND SELECTIVITY IN DC POWER DISTRIBUTION SUB-SYSTEMS

DC power distribution sub-systems are essential components of electrical power facilities since they allow the carrying out of vital facility functions in normal operation even in the event of a collapse in grid voltage. Therefore, such systems should be a reliable and safe source of electrical power. When taking into consideration that the manner of terminating DC current is significantly different from terminating AC current, it is important that, when designing DC power distribution sub-systems in electrical power facilities, care be taken concerning their characteristics. A proper selection of protection devices (low-voltage fuses and circuit breakers) and their proper allocation according to distribution protection levels achieves protection selectivity. This paper presents the basic types of protection devices and their possible uses in DC power distribution sub-systems and the manner of achieving protection selectivity.

Asset Administration Shell 기반 전기자동차 실시간 모니터링 시스템 구현

Amid the digital transformation paradigm, the concept of a digital twin that can provide a seamless connection between the physical and information worlds was announced as a critical element. Asset Administration Shell (AAS) is emerging as a core technology for implementing a digital twin. AAS is a meta-model specification that can represent all the characteristics and information of the asset in the information world. In this study, we implemented a real-time electric vehicle monitoring system to verify and analyze the characteristics of battery pack operations. A monitoring system collects and stores almost all data on communication between electric vehicle facilities such as the inverter, battery pack, brake system, air conditioning, vehicle location, and vehicle direction depending on the driver’s operations. Furthermore, we developed an AAS meta-model for electric vehicle information to provide a standardized interface for applications. In this paper, we demonstrate a simple example in which the behavior of a battery pack can be analyzed based on the action of the electric vehicle.

변압기 비율차동계전기의 보호협조 운용방안에 대한 알고리즘 개발

Recently, most electrical system failures are difficult to identify with the naked eye due to the trend of cutting-edge and mass capacity of electrical facilities, and the failure section is determined through the operation of the protective relay. In addition, the protection range of the protective relay is wide, and many hours, manpower and costs are involved in the identification of the correct fault site, and electrical safety is a problem. Therefore, in this paper, as a digital ratio differential relay of a power transformer, malfunction cases and occurrence mechanisms of RDR(Ratio Differential Relay), an electrical protection device installed as an automatic shut off device in the event of a transformer internal failure, are analyzed, and the ratio We propose an algorithm for preventing malfunction of differential relay. As a result of analyzing the malfunction characteristics of the ratio differential relay based on the implementation of the proposed algorithm and test device, when the ratio differential relay is operated according to the proposed algorithm, it is possible to prevent malfunction without separate wiring and changing the CT(Current Transformer) installation location. Therefore, it was possible to confirm that the algorithm presented in this paper is useful.

Specific Features of Operation of Distributed Generation Facilities Based on Gas Reciprocating Units in Internal Power Systems of Industrial Entities

The creation of a decentralized low-carbon energy infrastructure is the main trend in the development of the electric power industry in many countries. Distributed generation facilities (DGs) based on gas reciprocating units (GRUs) are often built by industrial entities for the efficient utilization of secondary energy resources in order to minimize the environmental impact. Modern GRUs have some advantages, but they have design features that should be factored in when connecting them to the internal power systems of industrial entities. Incorrect consideration of possible operating conditions of GRU in their design can lead to their damage, excessive shutdowns, and disruptions in power supply to essential power consumers with significant damage and losses from undersupply of their products. Excessive shutdowns of GRUs are often caused by a non-selective choice of settings for relay protection devices or by load surges that exceed the allowable ones. With high availability factors, GRUs are disconnected five to eight times more often compared to large gas turbine and steam turbine power units. The large total power consumed by electric motors, as part of the load of an industrial entity, determines the nature and parameters of electromechanical transient processes during emergency disturbances. The presented analysis of issues facing real DG facilities relies on the acts of investigation into the causes of accidents. Calculations have shown that the action of the “Load Agreement Module” in the GRU excitation controller can provoke the occurrence of a voltage avalanche in the internal power system with a complete shutdown of the load. The paper presents recommendations on the choice of control algorithms and voltage settings for the GRU excitation controller. Technical solutions are given to prevent damage and excessive shutdowns of GRU in various operating conditions of the system, and to help ensure a reliable power supply to power consumers. The change in approaches to the design of DG facilities is substantiated in the light of their significant differences from other electric power facilities.

Hysteresis response of rotary friction dampers developed for seismic operational performance of non-structural components vulnerable to overturning

The electrical facilities in buildings play important roles in maintaining operational performance during and after earthquakes. In this study, rotary friction dampers were developed for electrical facilities vulnerable to overturning, and cyclic loading tests were performed for the corresponding sub-assemblies (comprising friction plates), aiming to investigate the hysteresis response(s) of the friction dampers. The primary test parameters included the number of bolts used for fabricating the friction plates, torque applied to the bolts for their fixation to the friction plates, and cyclic loading frequency. In total, three series of 24 full-scale friction damper specimens were fabricated and tested according to the guidelines specified in the Korean seismic design standard (KDS 41 17, 2019). Based on the test results, the mechanical characteristics and seismic performance of the friction dampers were assessed and investigated in details. A macro-analytical model was developed to simulate the load–displacement response of the friction dampers, and its prediction showed a good correlation with the experimental results. Finally, dynamic analysis was performed by applying the developed friction damper to the entire system (mold transformer). As a result of the analysis, the response displacement of the detail with friction damper was reduced by about 95% in the X-direction and about 70% in the Y-direction compared to the displacement of the conventional detail.

<b>Method for Estimating Equivalent Salt Deposit Density on Insulator Surfaces Using Meteorological and Topographical Information Provided by Public Institutions</b>

Traditionally, the design and maintenance of electric power facilities of electric railways in bay areas have been carried out according to a uniform classification of pollution based on distance from the coast and other factors. In order to improve the safety of these facilities and save labor for maintenance, it is necessary to subdivide this uniform classification according to the actual pollution situation. Therefore, we propose a method for estimating the Equivalent Salt Deposit Density on insulator surfaces at any point on an open section using meteorological and topographical information provided by public institutions.

전력패턴·제어특성·운전조건 데이터를 활용한 생산설비 이상 탐지를 위한 AI 모델링 방법 연구

Although it is necessary to maximize efficiency through systematic maintenance of production facilities, convergence of various professional technologies and knowledge such as materials, machinery, and electrical facilities is required. Systematic management is difficult due to the diversity of expensive measuring equipment and objects. In order to overcome such problems, various experiences (implicit knowledge) of field experts are converted into a form that computers can understand. AI modeling and inference results for production facility abnormalities and quality abnormalities based on translated data (labeling data) are provided on-site Visualization technology is needed for. ① Learning data are generated from raw data of production facilities (operating conditions, operating conditions, and power patterns). ② We present a Ranked-FBD-based visualization method that can compare expert experience and machine learning results. It is expected that the visualization method based on Ranked-FBD and generation of learning data through this study can predictively diagnose unit production facilities (injection molding, press, fusion, painting, etc.) of small and medium-sized parts manufacturers and provide a customized solution.

An Interacting Negative Feedback Mechanism in a Coupled Extreme Weather–Humans–Infrastructure System: A Case Study of the 2021 Winter Storm in Texas

Extreme weather has long been a threat to human life and critical infrastructures. Previous studies have focused on the reliability and vulnerability of single or interdependent infrastructures under extreme weather threats. However, knowledge of the interactions between coupled real-world complex systems, especially the cascading failure process induced by external shocks, is essential, but the interactions receive less attention. Here, we took the historical winter storm of Texas that occurred in February 2021 as a case study and collected multisource data to explore the interaction between humans and the power system affected by extreme weather. A connectivity-based network was proposed to analyze the connectivity robustness and simulate the cascade of overload failures under random and malicious attacks. Results showed that this network presents higher robustness under random attacks in terms of network connectivity. However, a highly heterogeneous distribution of load was shown in this network, making it particularly vulnerable to attacks and easier to trigger cascading failures. An interacting negative feedback mechanism was discovered in this coupled extreme weather–humans–infrastructure system. Extreme weather events directly caused physical failure in infrastructures, while their impact on individuals stimulated the power demand for heat. An increase in demand further intensified the load on the power network, which induced functional failure in infrastructure systems and finally aggravated the adverse impact on people as end-users in return. This feedback loop inspired us to reconsider the relationship among natural disasters, critical infrastructure, and humans. Furthermore, even under the background of climate change, the impact of extremely cold weather on electric infrastructures is still worthy of attention since the fluctuation of yearly minimum temperature outstood in eastern Texas, where the majority of the population and electric transmission facilities are located. Thus, it is noteworthy to integrate the interaction between systems in the vulnerability assessment of infrastructure systems or the impact prediction of intense external shocks in future research.

Analysis of nonequilibrium atomic and molecular nitrogen radiation in pure N2 shockwaves

This paper presents an analysis of data previously reported from a test series in the Electric Arc Shock Tube Facility for incident shocks composed of pure nitrogen. The present work focuses on the lowest velocity measured in the test (approximately 7 km/s) where both molecular and atomic radiation are significant. Analysis of the spectral data with the NEQAIR radiative transport code obtains post-shock trends in temperature and number densities of the states of N2 and atomic N. The results suggest that chemical, and possibly thermal, equilibrium has not been obtained within the distance/time measured (about 5 cm/80 µs). In the nonequilibrium region of the shock, differences between rotational temperatures of different species are observed, as well as differences between rotational and vibrational temperatures. Population of rotational states above the dissociation limit is observed to occur over a distance of several cm. Finally, these data suggest that predissociation strongly affects the C3Πu state of N2, leading to a lower measured radiation than predicted. An effective average pre-dissociation rate is shown to produce reasonable agreement under quasi-steady state approximation.

The Current Situation and Development of Electric Vehicle Energy Supply Facilities Construction Based on Structural Changes

The Current Situation and Development of Electric Vehicle Energy Supply Facilities Construction Based on Structural Changes

Consideration of Harmonic Distortions in Modeling the Electromagnetic Fields Generated by Power Lines Feeding Railway Traction Substations

In setting up intelligent electric networks, special attention is paid to the operational safety of electric power facilities and reduction of their negative impact on the personnel and environment. Significant electromagnetic field intensity levels can be observed at such objects. To ensure electromagnetic safety under the modern conditions characterized by large-scale introduction of digitalization tools, it is necessary to develop electromagnetic field digital modeling algorithms. Adequate models of the electromagnetic field generated by power transmission lines can be obtained on the basis of methods for determining the electric power system operation modes in phase coordinates. A methodology for analyzing electromagnetic safety has been developed on the basis of such models, which differs from the known approaches in being systematic, versatile, adequate to the external environment, and comprehensive. By using the newly developed methodology, it is possible to determine the intensity of electromagnetic fields generated by multi-wire transmission lines taking into account higher harmonic components of currents and voltages. Under the conditions of digitalizing the electric power industry, the use of the proposed methodology for practical applications will make it possible to analyze the conditions of electromagnetic safety in electric power systems on a scientifically sound basis and develop measures for its further improvment.

Planning of electric vehicle charging infrastructure under the Background of Big Data

Today, the problems of power consumption and environmental pollution caused by road traffic are very serious. Automobiles produce large amounts of carbon monoxide and nitrogen, dust, and particles, which are the primary user of the fuel. Unconventional design methods will prevent the international process of replacing fuel-filled vehicles with electric vehicles. The promotion and adoption of electric vehicles can effectively alleviate these problems, but the planning of electric vehicle charging facilities needs to be resolved as soon as possible. The state-of-the-art mode and power model of public charging equipment proposed in this paper can solve the problem of positioning charging equipment in large-scale transmission networks and research on related charging materials and location planning and energy model design methods that are beneficial to the future development.

О НЕСОВЕРШЕНСТВЕ ТЕРМИНОЛОГИИ В ОБЛАСТИ РАЗВИТИЯ ОБЪЕКТОВ ЭЛЕКТРОЭНЕРГЕТИКИ

The regulatory documentation in the electrical power industry contains such terms as “technical re-equipment”, “reconstruction”, “expansion”, “modernization”, “repair” and “operation”. Some of them are easily defined while the specific differences of some terms require deeper study of regulatory documents in the technical, legal, account-ing and tax areas. At the same time, the incorrect use of these terms can lead to problems both in industrial activities and in related areas, and lead to precedents in judicial practice. In order to establish the differences between the designated terms, the article provides an analysis of normative documents, analyzing the concepts used in them. It attempts to establish the meaning and scope of the terms and the semantic links between them, while analyzing cases of practical application. The study provides recommendations on the use of each of these terms and a conclusion is made about the need to improve the existing regulatory and methodological framework concerning the modernization of electric power facilities.

Manhole Quality Management and Sensing Using IOT

'A novel design of a model method of quality management of manholes in metropolitan cities that can improve the efficiency of civic bodies in an urban and technology driven country'. In these recent times, aging and outdated public sewers and underground networks and facilities have caused increased needs for systems that support the robust maintenance and management of social infrastructure. There are dire needs for measure regarding manholes involved in water, sewage, gas and electric facilities, including the supplementary countermeasures to prevent the covers from being subjected to damaged or displaced due to ill manner of maintenance, aging or torrential rainfall that exceeds its drainage capacity. There is also concern regarding covers being stolen or manholes being used in acts of terrorism, and efforts to solve the problems caused by manholes are required so that people can live in a safe environment and are not subjected to any freak accidents or unfortunate mishaps. This social concern can be monitored and solved with the integration of Internet of Things (IoT) will enable us to effectively solve the problems regarding underground network of sewers. Internet of Things (IoT) consists of real-life objects, communication devices attached to sensor networks in order to provide communication and automated actions between real world and information and data driven world.

BIO-INSPIRED MULTIPLE SCALES PLACE RECOGNITION FOR ELECTRIC SUBSTATIONS

Abstract. We could get many helpful information and results from satellite remote sensing images and aerial images, including disaster monitoring, grid hidden danger identification, and electricity consumption management. In the recent years, novel computer vision and deep neural network have got a lot of attention in many fields because of mimicking mammalian cognitive mechanism as much as possible. With the in-depth of mammalian cognitive and motor mechanisms research, people trend to adopt these reliable and efficient methods for power grid management and maintenance.For utilizing computing resources and improving analysing efficiency flexibly, we propose an assessing and verification framework based on bio-inspired perception and understanding, which summarizes the most appropriate image scale in the electric facilities place recognition. The proposed framework consists of different scenes aerial images datasets, several electric facilities place recognition methods, and credible evaluating methods mimicking mammals. Firstly, we gather satellite remote images and aerial images of sufficient electric power facilities in the United States via Google Earth and other public datasets. Then, several typical place recognition methods are adopted to testing recognition ability of multi-scale perception results, like SAD, NetVLAD, and GIST descriptor. To get more reliable result, multi-units and multi-scenes experiments are implemented roundly. After all experiments and evaluations, we could get that the most appropriate image scale is 1000 m size and the highest recognition accuracy of electric power facilities location is 500 m. Conclusion in our article shows the recommended perception form and scale closest to human cognition in the power grid management and maintenance.