scholarly journals Calculations, norming and reducing of electrical energy losses in city electrical networks

2019 ◽  
Vol 21 (3) ◽  
pp. 46-54
Author(s):  
A. V. Lykin ◽  
E. A. Utkin
Keyword(s):  
High Voltage ◽  
Power Transmission ◽  
Low Voltage ◽  
Demand Curve ◽  
Electrical Energy ◽  
Electrical Network ◽  
Energy Losses ◽  
Capital Investments ◽  
Electrical Networks

The article considers the feasibility of changing the structure of a distribution electrical network by transferring points of electricity transformation as close to consumers as possible. This approach is based on installation of pole-mounted transformer substations (PMTS) near consumer groups and changes the topology of the electrical network. At the same time, for groups of consumers, the configuration of sections of the low-voltage network, including service drops, changes. The efficiency of approaching transformer substations to consumers was estimated by the reduction in electrical energy losses due to the expansion of the high-voltage network. The calculation of electrical losses was carried out according to twenty-four hour consumer demand curve. To estimate the power losses in each section of the electrical network of high and low voltage, the calculated expressions were obtained. For the considered example, the electrical energy losses in the whole network with a modified topology is reduced by about two times, while in a high-voltage network with the same transmitted power, the losses are reduced to a practically insignificant level, and in installed PMTS transformers they increase mainly due to the rise in total idle losses. The payback period of additional capital investments in option with modified topology will be significantly greater if payback is assessed only by saving losses cost. Consequently, the determination of the feasibility of applying this approach should be carried out taking into account such factors as increasing the reliability of electricity supply, improving the quality of electricity, and increasing the power transmission capacity of the main part of electrical network.

scholarly journals Analysis of unbalanced load low-voltage electrical networks operating modes

2021 ◽  
Vol 295 ◽  
pp. 02005
Author(s):  
Igor Naumov ◽  
Sergey Podyachikh ◽  
Dmitri Ivanov ◽  
Alexander Tretyakov ◽  
Andrey Bastron
Keyword(s):  
Low Voltage ◽  
Residential Buildings ◽  
Electrical Energy ◽  
Operating Mode ◽  
Electrical Network ◽  
Electrical Networks ◽  
Power Losses ◽  
Voltage Unbalance ◽  
Operating Modes ◽  
Unbalanced Load

The article discusses distribution electrical networks 0.38 kV operating modes, feeding individual residential buildings. The electrical energy parameters measurement were certified RESURS-UF2M device carried out. The currents and voltages time diagrams based on the measurements made and using Matlab technologies were constructed. It is established that the level of phase currents unbalance is quite high and causes significant three-phase power supply system unbalance voltage accordingly. The power of quality indicators - calculations, characterizing voltage unbalance were made, which were based on the measurements and the computer program “Asymmetry” was used. As well as the additional power losses coefficient determining by the phase currents unbalance, were calculations. Time diagrams these indicators are constructed and their analysis were made. As a result, the power of quality is significantly reduced by unbalance power consumption in the studied electrical network were founded. At the same time, the additional power losses are significant increases. Specific recommendations for the normalization electrical network-operating mode are given.

scholarly journals Ensuring an effective voltage regime in the electrical network when powering ships of the technical fleet and floating objects from the shore

2021 ◽  
Vol 2131 (5) ◽  
pp. 052047
Author(s):  
Y Denchik ◽  
E Ivanova ◽  
V Salnikov ◽  
S Gorelov ◽  
D Zubanov
Keyword(s):  
Electromagnetic Compatibility ◽  
Power Transmission ◽  
Low Frequency ◽  
Electrical Network ◽  
Electromagnetic Disturbance ◽  
Electrical Networks ◽  
Reverse Sequence ◽  
Effective Voltage ◽  
Automated Determination

Abstract The article deals with topical issues of reducing the asymmetry of linear voltages in the electrical networks of water transport enterprises. Asymmetric modes in the electrical network are researched, which defined the need for automated determination of conductive electromagnetic disturbance. A mathematical description of the occurrence process and strategy for determining the conductive low-frequency electromagnetic disturbance by the voltage asymmetry coefficient in the reverse sequence are presented. The parameters of this coefficient are described: mathematical expectation, standard deviation, probability of occurrence during the calculation period. A mathematical model is obtained that represents a conductive electromagnetic disturbance and explains the probability of its occurrence. A method of automated determination of conductive electromagnetic disturbance has been developed. A software product is presented (certificate of registration No. 2016661752), which allows processing the voltage coefficients obtained as a result of measurements in the reverse sequence. The conductive disturbance is determined for the purpose of suppression and ensuring electromagnetic compatibility. To ensure an effective mode by powering ships from the shore and to increase the efficiency of power transmission, a strategy for voltage symmetry in the electrical network is presented.

scholarly journals Operation Modes of HV/MV Substations

2009 ◽  
Vol 25 (25) ◽  
pp. 81-86
Author(s):  
Josifs Survilo ◽  
Antons Kutjuns
Keyword(s):  
High Voltage ◽  
Low Voltage ◽  
Warm Season ◽  
Electrical Energy ◽  
Cold Season ◽  
Power Losses ◽  
Medium Voltage ◽  
The Third ◽  
Operation Modes ◽  
Mode 3

Operation Modes of HV/MV SubstationsA distribution network consists of high voltage grid, medium voltage grid, and low voltage grid. Medium voltage grid is connected to high voltage grid via substations with HV/MV transformers. The substation may contain one, mostly two but sometimes even more transformers. Out of reliability and expenditure considerations the two transformer option prevail over others mentioned. For two transformer substation, there may be made choice out of several operation modes: 1) two (small) transformers, with rated power each over 0.7 of maximum substation load, permanently in operation; 2) one (big) transformer, with rated power over maximum substation load, permanently in operation and small transformer in constant cold reserve; 3) big transformer in operation in cold season, small transformer-in warm one. Considering transformer load losses and no load losses and observing transformer loading factor β it can be said that the mode 1) is less advantageous. The least power losses has the mode 3). There may be singled out yet three extra modes of two transformer substations: 4) two big transformers in permanent operation; 5) one big transformer permanently in operation and one such transformer in cold reserve; 6) two small transformers in operation in cold season of the year, in warm season-one small transformer on duty. At present mostly two transformers of equal power each are installed on substations and in operation is one of them, hence extra mode 5). When one transformer becomes faulty, it can be changed for smaller one and the third operation mode can be practiced. Extra mode 4) is unpractical in all aspects. The mode 6) has greater losses than the mode 3) and is not considered in detail. To prove the advantage of the third mode in sense of power losses, the notion of effective utilization time of power losses was introduced and it was proven that relative value of this quantity diminishes with loading factor β. The use of advantageous substation option would make it possible to save notable amount of electrical energy but smaller transformer lifetime of this option must be taken into account as well.

scholarly journals Influence of smart metering systems on increasing the accuracy of calculation electrical power losses in electrical networks

2020 ◽  
Vol 220 ◽  
pp. 01026
Author(s):  
Timur Musaev ◽  
Marat Khabibullin ◽  
Ramil Kamaliev ◽  
Oleg Fedorov ◽  
Ilgiz Valeev ◽  
...  
Keyword(s):  
Low Voltage ◽  
Accurate Determination ◽  
Electrical Power ◽  
Electrical Energy ◽  
Actual Data ◽  
Load Factor ◽  
Electrical Networks ◽  
Operating Load ◽  
Using Data ◽  
Increase In Accuracy

The article discusses the possibility of using data from smart electricity meters (SEM) to increase the accuracy of calculation losses in 0.4 kV low-voltage networks. An increase in accuracy can be achieved using actual data about the load graph of electricity consumers (in this case, 6(10)-0.4 kV transformer substations are meant). To date, the operating load factor is taken equal to 0.5, which does not always correspond to the actual data. Using SEM, actual load graphs can be obtained, which enable more accurate determination of the operating load factor. Consequently, the accuracy of calculation of electrical energy losses will be increased.

A Model of Voltage Distribution and Change of Current in the Network Containing Unaccounted Electricity Consumption

Vestnik MEI ◽  
2021 ◽  
pp. 91-99
Author(s):  
Ivan M. Kazymov ◽  
◽  
Boris S. Kompaneets ◽  
Keyword(s):  
Graphical Representation ◽  
Low Voltage ◽  
Electricity Consumption ◽  
Distribution Networks ◽  
Electrical Network ◽  
Electrical Networks ◽  
Voltage Distribution ◽  
Electrical Grids ◽  
Proposed Model ◽  
Nominal Voltage

The aim of the study is control of commercial losses in electrical grids, especially in low voltage grids, which is one of the priority lines of activities conducted by electric network companies. The complexity of solving this problem is stemming from the difficulty of exactly locating the commercial loss occurrence place under the conditions of extensively branched low and medium voltage electrical networks. Various methods are currently used to determine the commercial loss occurrence places. However, no effective methods have been created for determining the fact and place of unaccounted electricity consumption in networks under the conditions of performing remote analysis of networks based on the data from modern electricity meters used in the automated fiscal electricity metering system. These difficulties can be overcome by developing a model of voltage distribution and change of current in distribution networks of the 0.4--35 kV nominal voltage levels. A model of voltage distribution and changes of current for a network containing unaccounted electricity consumption is proposed. The effectiveness of using the proposed model has been theoretically substantiated; its applicability limits are defined, and the accuracy of the obtained results is estimated. Graphical representation of the proposed model, which is one of the electrical network digital imaging forms, can be used to analyze electrical networks for revealing if there is unaccounted electricity consumption in them. By using the proposed model of voltage distribution and change of current in the network, it is possible to represent the electrical network as a set of electrical parameters to analyze electrical networks for the presence of commercial losses.

Idejno rešenje regionalnog Data Centra kod Beograda napajanog iz obnovljivih izvora energije

2021 ◽  
Vol 23 (3) ◽  
pp. 10-17
Author(s):  
Ivan Vujović ◽  
Željko Đurišić ◽  
Keyword(s):  
High Voltage ◽  
Power Supply ◽  
Wind Farm ◽  
Low Voltage ◽  
Power Transformer ◽  
Renewable Energy Sources ◽  
Geographical Location ◽  
Electrical Energy ◽  
Economic Benefits ◽  
Infrastructure Development

Telecommunications and computer equipment centralisation trends for the purpose of achieving economic benefits, usage of technological innovations and new technical solutions implementation leads to the requirements for building bigger Data Centres (DCs). An increase in the size of the DC facility i.e. the number of racks inside occupied with equipment and the number of devices that enables the proper functioning of that equipment leads to necessarily power energy requirements increasing for power supply. For the DCs that require a large amount of energy, the building of their own, usually renewable energy sources (RES) is cost-effective. In such a caser, RES are primary and Power System (PS) is secondary and redundant power source. A concept of a DC primary powered from RES is presented in this paper. Generated electrical energy in RES is transmitted in PS through high voltage switch-gears (SGs) while DC is power supplied from PS through low voltage, medium voltage and high voltage SG-s. For the purpose of realisation of such facility, it is necessary to enable adequate conditions related to geographical location, physical access to the facility, possibility of connecting to the PS and possibility of connecting to the telecommunications centres. Based on carried out researches related to RESs potential, available roads, power supply infrastructure and telecommunication infrastructure, development conditions for DC on location near to Belgrade, close to power transformer station „Belgrade 20“ are analysed in this paper. From the aspect of DC power supply, proposed solution includes wind farm, solar plant and landfill gas power plant, as well as related SGs. Telecommunication connections from DC to the PS and other important telecommunication centres are provided. These connections are realised through optical cables placed next to the electrical lines and cables, and, when that is not possible, placed independently in the ground. The design of the DC interior is given and calculations of the required electrical energy for the power supply of the equipment and devices in the facility are performed. Based on calculation results, capacity calculation of the RES and calculation of SGs are performed. Design of the interior optical connections inside DC is also given. A General assessment of the investment and economics of building such DC are given at the end of the paper.

scholarly journals Placement of shunt reactors in high-voltage network using fuzzy constraints

2019 ◽  
Vol 139 ◽  
pp. 01052
Author(s):  
Arif Hashimov ◽  
Huseyngulu Guliyev ◽  
Aytek Babayeva
Keyword(s):  
High Voltage ◽  
Reactive Power ◽  
Power Transmission ◽  
Operation Mode ◽  
Ease Of Use ◽  
Electrical Network ◽  
Control Voltage ◽  
Fuzzy Constraints ◽  
Definition Of ◽  
Shunt Reactors

In recent years, controlled shunt reactors (CSR) relevant to the class of FACTS facilities have been widely used to control voltage modes and reactive power flows in the high-voltage electrical network. The selection of location, as well as the definition of the law of CSR control in the conditions of stochastic variability of the operation mode of high-voltage power transmission, are associated with numerous technical and economic factors. At the same time, such constraint conditions as ease of use, performance efficiency, purpose and location in the system, as well as the period of commissioning should be taken into account. In the proposed procedure these factors are considered as fuzzy constraints. The procedure of CSR placement in the 330 kV electrical network of Azerenergy system for control of reactive power flows taking into account the mentioned fuzzy constraints is proposed. The obtained simulation results confirm the advantage of the proposed procedure.

scholarly journals Timely determination of static stability margins in power supply systems equipped with distributed generation installations

2021 ◽  
Vol 25 (1) ◽  
pp. 31-43
Author(s):  
Yu. N. Bulatov ◽  
A. V. Kryukov ◽  
К. V. Suslov ◽  
A. V. Cherepanov
Keyword(s):  
Distributed Generation ◽  
Power Supply ◽  
Computer Modelling ◽  
Dynamic Modelling ◽  
Electrical Network ◽  
Electrical Networks ◽  
Stability Margins ◽  
Emergency Control ◽  
Supply Systems

The article aims to develop a methodology to ensure timely determination of the margins of static aperiodic stability in power supply systems, at the nodal points of which distributed generation units are installed. The authors used mathematical methods and algorithms based on the application of limiting regime equations. Transitional processes were analysed for various points in the space of controlled mode parameters according to the simulation modelling in Matlab using the Simulink and SimPowerSystems packages. On the basis of the obtained results, an effective technique for analysing stability margins in electrical networks with distributed generation units was implemented. This method is applicable in design problems, as well as in operational and emergency control. The conducted theoretical analysis and computer modelling showed the effectiveness of the proposed methodology for calculating stability margins; the nondegeneracy of the Jacobi matrix of limiting regime equations at the solution point ensures the guaranteed reliability of the results. It was shown that an alternative approach to solving the problem of timely determination of aperiodic stability margins can be implemented on the basis of limiting regime equation with increased nonlinearity. Dynamic modelling of an electrical network with distributed generation units confirmed the correctness of determining the stability margins calculated using limiting regime equations. The developed technique can be recommended for practical use in the design of power supply systems or in operational control of synchronous generators. In particular, the presented methodology can be used to implement a multi-agent emergency control system for distributed generation installations located in generalpurpose distribution electrical networks. 

scholarly journals Experimental determination of the parameters of the eight-pole

2019 ◽  
Vol 21 (4) ◽  
pp. 85-94
Author(s):  
G. A. Bol'shanin ◽  
M. P. Plotnikov ◽  
M. A. Shevchenko
Keyword(s):  
Transmission Line ◽  
Experimental Determination ◽  
Transmission Lines ◽  
Power Transmission ◽  
Quantitative Relationship ◽  
Electrical Energy ◽  
Indirect Measurement ◽  
Power Line ◽  
Accurate Information

To determine the results of the transmission of electrical energy through the power line from the source to the consumer, it is necessary to have accurate information about the parameters of such line. Determining these parameters for operating lines with a minimum error is quite a laborious process. But if a researcher is interested only in voltages and currents at the end and at the beginning of a homogeneous section of a three-wire transmission line, then it is sufficient to use the theory of multipoles. In particular, the theory of eight-poles. The article presents the method of experimental determination of the longitudinal and transverse parameters of the studied transmission line. The study used the methods of natural experiment using an appropriate fleet of electrical devices, and methods of indirect measurement of the desired parameters. The experiment consists of six stages; on the basis of the obtained data, it becomes possible to determine the numerical values of the main parameters of the studied section of power transmission lines, with which it is possible to establish a quantitative relationship between the input and output characteristics of electrical energy. In addition, the described method, in principle, can be applied to the analysis of active eight-terminal networks of a similar design. This means that the proposed methodology can provide a comprehensive analysis of the studied object and will help to identify the parameters of an overhead power line at the construction stage or for its connection to the consumer. The article presents the experimental setup scheme, describes the experimental methods, and estimates the error of the calculation results.

scholarly journals AUTOMATED WORKPLACE OF THE ELECTRICAL NETWORK DISPATCHER

2019 ◽  
pp. 23-29
Author(s):  
Shamil Abbasovich Turpishchev ◽  
Andrey Vladimirovich Rogov ◽  
Alexey Vladimirovich Anikeev ◽  
Sergey Vladimirovich Golovko
Keyword(s):  
Management System ◽  
Electrical Energy ◽  
Information Management System ◽  
Power Industry ◽  
Basic Function ◽  
Normal Operation ◽  
Electrical Network ◽  
Technological Equipment ◽  
Electrical Networks ◽  
Monitoring And Control

Currently, a great number of organizations are seeking to automate the workflow and to use electronic information. The article considers a method to increase reliable and economic distribution of electrical energy by means of supporting highly effective operational and technological activities of distribution power grid companies, by complex automation of collecting, processing, transferring information and making decision on executing a basic function of operational and technological control. The main problems of transforming technological equipment and electrical networks into a single information management system of the dispatcher monitoring have been considered. According to the Federal Law “On power industry”, the purpose of the system of supervisory control in power industry is to support the reliable power supply and quality of electrical energy that correspond to the requirements of technical rules and requirements, as well as other regulations set by organizational and distributive acts. In order to achieve the goals there is developing the in-house network management system integrated into the general hierarchical structure, which increases its efficiency. The interaction of subjects of a power facility is defined by the needs of operational and technological monitoring and control for power engineering. Using the automated software system will reduce electricity shortage, prevent failures in the normal operation of the power system and improve its reliability due to the completeness of information on technological equipment operation.

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