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 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 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.

scholarly journals Algorithms and models of power losses in circuit breakers installed in networks

Vestnik MGTU ◽  
2020 ◽  
Vol 23 (4) ◽  
pp. 345-353
Author(s):  
E. I. Gracheva ◽  
A. N. Gorlov ◽  
A. N. Alimova
Keyword(s):  
Power Supply ◽  
Low Voltage ◽  
Technical Condition ◽  
Active Power ◽  
Operating Conditions ◽  
Public Utility ◽  
Electrical Networks ◽  
Power Losses ◽  
Circuit Breakers ◽  
Technical Parameters

Determination of the main characteristics of the topology and technical condition of equipment underoperating conditions is necessary for analyzing and assessing power and electricity losses in intrashoplow-voltage industrial power supply networks. A comparative analysis of the technical characteristicsof automatic circuit breakers VA57-31 (KEAZ), NSX100 TM-D (Schneider Electric), DPX3 160 (Legrand), Tmax XT1 TMD (ABB) has shown that the main technical parameters of the machines are close in their values. At that it has been found out that automatic switches of the BA57-31 series have the lowest value of power losses per pole (7.5 W), whereas the automatic switches of the Tmax XT1 TMD series have the highest value (10 W). Thus, under the operating conditions of the equipment, the lowest value of power and electricity losses is characteristic of low-voltage electrical networks with installed circuit breakers of the BA57-31 series, and the highest value of losses is noted in in-shop systems with installed circuit breakers Tmax XT1 TMD. Using catalog data, the dependences of active power losses in circuit breakers on rated currents have been established; the algorithms have been developed and the obtained dependences have been modeled using approximating functions. The standard deviation of the compiled approximating functions has been calculated. Analytical expressions of the dynamics of power losses per pole have been determined as a function of the rated current. The graphical dependences of the investigated parameters of low-voltage equipment have been presented. The developed models are recommended to be used to increase the reliability of the assessment and refinement of the amount of active power and electricity losses in low-voltage electrical networks of industrial power supply systems, agrotechnical complexes, and enterprises of the public utility sector.

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.

scholarly journals Influence of resistance of contact units of switching devices on the electric power losses in shop networks of low tension

2019 ◽  
Vol 124 ◽  
pp. 02013 ◽  
Author(s):  
D. D. Micu ◽  
I. V. Ivshin ◽  
E. I. Gracheva ◽  
O. V. Naumov ◽  
A. N. Gorlov
Keyword(s):  
Electric Power ◽  
Low Voltage ◽  
Technical Condition ◽  
Electrical Networks ◽  
Power Losses ◽  
Switching Device ◽  
Low Tension ◽  
Switching Equipment ◽  
Voltage Switching ◽  
Switching Devices

This paper presents calculation of resistance of tightening contact joints of switching devices. It allows considering the technical condition of low-voltage switching equipment and to specify energy emitted in the switching device in the mode of electrical networks operation is presented in the article.

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.

scholarly journals On the choosing the installation location the balancing devices in low-voltage distribution electric networks

2021 ◽  
Vol 2094 (5) ◽  
pp. 052012
Author(s):  
I V Naumov ◽  
S V Podyachikh
Keyword(s):  
Power Quality ◽  
Low Voltage ◽  
Experimental Studies ◽  
Distribution Networks ◽  
Electrical Networks ◽  
Process Change ◽  
Electric Networks ◽  
Concentrated Load ◽  
Operating Modes ◽  
Three Phase

Abstract The experimental studies result on the power quality and additional power losses analysis caused by the asymmetric modes occurrence in three-phase four-wire 0.38 kV electrical networks are considered. The operating modes 38 kV networks several types simulation – with power take-off nodes distributed along the power line, and an electric network with a concentrated load is carried out. The programs have been developed that allow to assess the change in indicators characterizing asymmetric modes, as well as programs that allow us to visualize this process change. The most installing special symmetrical devices appropriate places in electric networks with a distributed load (rural electric distribution networks) and concentrated power take-off nodes electric networks (urban electric networks) have been identified to minimize losses and improve the power quality. A numerical studied indicators analysis was performed.

scholarly journals Line voltage asymmetry in closed electrical networks with distributed generation as a source of electromagnetic interference

2021 ◽  
Vol 2131 (5) ◽  
pp. 052004
Author(s):  
A Antonov ◽  
D Ivanov ◽  
Y Denchik ◽  
E Ivanova ◽  
M Ivanov ◽  
...  
Keyword(s):  
Distributed Generation ◽  
Electromagnetic Interference ◽  
Electromagnetic Compatibility ◽  
Low Frequency ◽  
Electrical Network ◽  
Technical Equipment ◽  
Electrical Networks ◽  
Electronic Resource ◽  
Voltage Unbalance ◽  
State Registration

Abstract The article reveals relevance of the problem of unbalance of line voltages in closed electrical networks with distributed generation as a source of electromagnetic interference, in particular, the problem of electromagnetic compatibility of coastal and ship technical equipment. There is presented mathematical description of the process of occurrence of conductive low-frequency EMF by the voltage unbalance coefficient in the reverse sequence and an algorithm for finding it; using the equations, parameters of this coefficient are described, such as mathematical expectation, standard deviation, probability of occurrence for the billing period, as a result, a computer program has been developed to calculate these parameters; a method for processing the obtained data of power quality indicators according to the found coefficient has been developed; an algorithm for balancing voltages in an electrical network based on finding the most optimal power supply scheme for end consumers (certificate of state registration of an electronic resource No. 23664).

scholarly journals Flexibility Assessment of Multi-Energy Residential and Commercial Buildings

Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2704
Author(s):  
António Coelho ◽  
Filipe Soares ◽  
João Peças Lopes
Keyword(s):  
Large Scale ◽  
Residential Buildings ◽  
Renewable Energy Sources ◽  
Energy Systems ◽  
Energy System ◽  
Commercial Buildings ◽  
Electrical Network ◽  
Electrical Networks ◽  
Technical Problems ◽  
Integration Of Renewables

With the growing concern about decreasing CO 2 emissions, renewable energy sources are being vastly integrated in the energy systems worldwide. This will bring new challenges to the network operators, which will need to find sources of flexibility to cope with the variable-output nature of these technologies. Demand response and multi-energy systems are being widely studied and considered as a promising solution to mitigate possible problems that may occur in the energy systems due to the large-scale integration of renewables. In this work, an optimal model to manage the resources and loads within residential and commercial buildings was developed, considering consumers preferences, electrical network restrictions and CO 2 emissions. The flexibility that these buildings can provide was analyzed and quantified. Additionally, it was shown how this model can be used to solve technical problems in electrical networks, comparing the performance of two scenarios of flexibility provision: flexibility obtained only from electrical loads vs. flexibility obtained from multi-energy loads. It was proved that multi-energy systems bring more options of flexibility, as they can rely on non-electrical resources to supply the same energy needs and thus relieve the electrical network. It was also found that commercial buildings can offer more flexibility during the day, while residential buildings can offer more during the morning and evening. Nonetheless, Multi-Energy System (MES) buildings end up having higher CO 2 emissions due to a higher consumption of natural gas.

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