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.

Analysis of operation of Oblkommunergo electric networks of Irkutsk Region

2021 ◽  
Vol 14 (3) ◽  
pp. 100-110
Author(s):  
I. V. Naumov
Keyword(s):  
Low Voltage ◽  
Average Duration ◽  
Electric Energy ◽  
Distribution Networks ◽  
Operational Reliability ◽  
Electrical Networks ◽  
Electric Networks ◽  
Public Media ◽  
Irkutsk Region ◽  
Graphic Editor

Analysis has been performed of the operation of electric distribution networks of ten branches of Oblkommunenergo (OKE) of Irkutsk Region [1]. Based on the data on the operation of these networks published in public media, algorithms and computer programs for the Matlab graphic editor are compiled, which are used for plotting time diagrams that characterize the operation of the electrical networks under consideration. The balance changes are shown in the transmission of electric energy into the OKE networks and from the OKE networks directly to consumers (high, medium and low voltage networks). The number of failures, the power supply interruption time and the amount of electricity undersupplied in each month of the year for each of the branches are considered. The months of the year are determined, in which the greatest and least damage occurs to the electrical networks of the OKE branches. Data are presented on the dynamics of annual wear of electric networks, planned activities and their annual implementation. The level of reliability is considered according to the established indicators of the average duration of interruptions in the transmission of electric energy in each calculated regulation period. It is shown that the combination of the main causes of failures largely depends on the natural-climatic and terrain specifics of the regions through which the routes of electric networks pass. As an example, data on the causes of failure in the electrical networks of one of the OKE branches are considered. The most and least damaged electrical networks of the considered OKE branches have been established. In conclusion, findings are formulated and recommendations are presented on minimizing outages based on the main types of failure causes for the purpose of increasing the operational reliability of the electrical networks under consideration.

scholarly journals Experimental study of quality and electricity losses in low voltage rural electric networks

2021 ◽  
Vol 23 (3) ◽  
pp. 209-222
Author(s):  
O. S. Rakhimov ◽  
D. N. Mirzoev ◽  
E. I. Grachieva
Keyword(s):  
Low Voltage ◽  
Experimental Studies ◽  
Digital Information ◽  
Electric Networks ◽  
Daily Consumption ◽  
Measuring Device ◽  
Three Phase ◽  
The Republic ◽  
Information Database

THE PURPOSE. Due to the increase in the number of farms in the Devashtichsky district of the Sughd region of Tajikistan, over the past 3-4 years, a disproportionate distribution of electricity in the 0.4 kV network has been observed. Unbalance currents of phase loads in relation to asymmetric phase voltages at the terminals of consumers of a three-phase network cause additional losses of electricity, which can reach 21% of the standard losses. In the decree of the President of the Republic of Tajikistan dated May 10, 2009 No. 29 “On energy saving and reduction of electricity losses” it is indicated that there is a need to study the quality of electricity in rural 0.4 kV networks and its compliance with GOST 32144. 2013, as well as an assessment of losses electricity in its distribution structure is an important task in the field of rural electricity. METHODS. A single-line diagram of a 0.4 kV network with initial parameters, which were refined during the survey of the network, and the current loads of outgoing lines were investigated. Experimental studies of the quality of electricity and assessment of the level of losses in the low- voltage network were carried out using a complex measuring device «Energotester» PKE - A - C4. RESULTS. The studies allowed obtaining data on the daily consumption of electricity in individual outgoing lines, information on the characteristics of consumers, digital information (database) on indicators of the quality of electricity in low-voltage networks. CONCLUSIONS. It has been established that the main factors influencing the losses of electricity in low-voltage networks are: incommensurability of the power of transformers of transformers and consumers, uneven loading of individual phases, a significant effect of individual converters on the quality of energy. Measures are forecasted to reduce losses and improve the quality of electricity in low-voltage rural networks of 0.4 kV.

scholarly journals Methodology for selecting the rated parameters of power transformers in the town’s electrical distribution networks in settlements

2021 ◽  
pp. 33-43
Author(s):  
Yu.A. Papaika ◽  
I.M. Lutsenko ◽  
IE.V Koshelenko ◽  
P.S. Tsyhan
Keyword(s):  
Load Capacity ◽  
Operating Mode ◽  
Distribution Networks ◽  
Heating Time ◽  
Power Transformers ◽  
Design Stage ◽  
Electrical Networks ◽  
Electric Networks ◽  
Actual Structure ◽  
Operating Modes

Purpose. To substantiate a technique of a choice of nominal power of power transformers for increase of  their use efficiency in distributive electric networks of the cities Methods. Analytical processing of statistical data. Findings. The paper solves the problem of efficient use of the installed power of transformers, their rational choice in the design of urban electrical networks. It was found that the choice of transformers according to classical methods causes a significant error and an overestimation of the rated power at the design stage. The method of reducing this error was developed for selecting the power of transformers of urban electrical networks. This method takes into account the predicted indicators of the operating modes of the equipment, the type of consumers, the load capacity of the equipment, the parameters of the operating mode and the environment, constant heating time of existing types of transformers that can be accepted for installation, the appropriate level of reactive load compensation. Originality The scientific novelty lies in the development of  the method for selecting the rated power of power transformers 6 (20) /0.4 kV urban distribution networks by comprehensive consideration of the parameters of typical consumers and their actual structure, which will effectively use transformer equipment for load capacity during the regulated period of their operation. Practical value. The obtained results show the increase in the efficiency of capital and operating costs by selecting a rational rated power of distribution transformers 6 (20) / 0.4 kV with ensuring the effective use of their load capacity in the conditions of electric grids of cities.

scholarly journals Experimental studies of the effect of a hybrid inverter on power quality

2021 ◽  
Vol 1 (3) ◽  
pp. 2-9
Author(s):  
YA.E. Shklyarskiy ◽  
◽  
A.N. Skam'in ◽  
O.S. Vasil'kov ◽  
◽  
...  
Keyword(s):  
Power Quality ◽  
Alternative Energy ◽  
Electromagnetic Compatibility ◽  
Experimental Studies ◽  
Parallel Operation ◽  
Electrical Networks ◽  
Active Resistance ◽  
Operating Modes ◽  
Voltage Distortion ◽  
Harmonic Composition

The integration of alternative energy sources and various technologies of distributed generation with power electronic converters in electrical networks leads to an increase in the diversity of the network, but at the same time to the tightening of the requirements of various standards, for exam-ple, a limited harmonic composition of the generated current, continuous operation of the device with voltage distortion, etc. Taking this fact into account, the paper presents the results of experi-mental studies of the effect of a hybrid inverter on power quality indicators at the point of common connection. A laboratory bench was developed. It consists of a three-phase hybrid inverter, a stor-age battery, a linear load in the form of an active resistance and a capacitor unit. The inverter has been connected to the power supply for parallel operation to supply the load in the form of active resistance. The modes of battery charging and power delivery to the network with two variations of the system resistance were investigated. The power output from the inverter varied from 500 W to 2 kW in the mode of generating electricity to the grid, and in the range from 50 to 300 W in the bat-tery charging mode. As a result of laboratory studies, the dependences of the total harmonic current distortion (THDI) were obtained for various operating modes of the inverter and system resistances. On the basis of the obtained results, an algorithm for the selection of methods and means to ensure electromagnetic compatibility during operation of the load and a hybrid inverter with energy storage was developed. It makes it possible to reduce the effect of hybrid inverters on the voltage distortion of the supply network.

scholarly journals Experimental study of quality and electricity losses in low voltage rural electric networks

2021 ◽  
Vol 23 (3) ◽  
pp. 224-237
Author(s):  
O. S. Rakhimov ◽  
D. N. Mirzoev ◽  
E. I. Grachieva
Keyword(s):  
Low Voltage ◽  
Experimental Studies ◽  
Digital Information ◽  
Electric Networks ◽  
Daily Consumption ◽  
Measuring Device ◽  
Three Phase ◽  
The Republic ◽  
Information Database

THE PURPOSE. Due to the increase in the number of farms in the Devashtichsky district of the Sughd region of Tajikistan, over the past 3-4 years, a disproportionate distribution of electricity in the 0.4 kV network has been observed. Unbalance currents of phase loads in relation to asymmetric phase voltages at the terminals of consumers of a three-phase network cause additional losses of electricity, which can reach 21% of the standard losses. In the decree of the President of the Republic of Tajikistan dated May 10, 2009 No. 29 “On energy saving and reduction of electricity losses” it is indicated that there is a need to study the quality of electricity in rural 0.4 kV networks and its compliance with GOST 32144. 2013, as well as an assessment of losses electricity in its distribution structure is an important task in the field of rural electricity. METHODS. A single-line diagram of a 0.4 kV network with initial parameters, which were refined during the survey of the network, and the current loads of outgoing lines were investigated. Experimental studies of the quality of electricity and assessment of the level of losses in the low- voltage network were carried out using a complex measuring device «Energotester» PKE - A - C4. RESULTS. The studies allowed obtaining data on the daily consumption of electricity in individual outgoing lines, information on the characteristics of consumers, digital information (database) on indicators of the quality of electricity in low-voltage networks. CONCLUSIONS. It has been established that the main factors influencing the losses of electricity in low-voltage networks are: incommensurability of the power of transformers of transformers and consumers, uneven loading of individual phases, a significant effect of individual converters on the quality of energy. Measures are forecasted to reduce losses and improve the quality of electricity in low-voltage rural networks of 0.4 kV.

scholarly journals D-PMU and 5G-Network-Based Coordination Control Method for Three-Phase Imbalance Mitigation Units in the LVDN

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2754
Author(s):  
Mengmeng Xiao ◽  
Shaorong Wang ◽  
Zia Ullah
Keyword(s):  
Mobile Networks ◽  
Control Method ◽  
Low Voltage ◽  
Control Unit ◽  
Distribution Networks ◽  
Optimal Operation ◽  
Positive Sequence ◽  
Measurement Unit ◽  
Control Units ◽  
Three Phase

Three-phase imbalance is a long-term issue existing in low-voltage distribution networks (LVDNs), which consequently has an inverse impact on the safe and optimal operation of LVDNs. Recently, the increasing integration of single-phase distributed generations (DGs) and flexible loads has increased the probability of imbalance occurrence in LVDNs. To overcome the above challenges, this paper proposes a novel methodology based on the concept of "Active Asymmetry Energy-Absorbing (AAEA)" utilizing loads with a back-to-back converter, denoted as “AAEA Unit” in this paper. AAEA Units are deployed and coordinated to actively absorb asymmetry power among three phases for imbalance mitigation in LVDNs based on the high-precision, high-accuracy, and real-time distribution-level phasor measurement unit (D-PMU) data acquisition system and the 5th generation mobile networks (5G) communication channels. Furthermore, the control scheme of the proposed method includes three control units. Specifically, the positive-sequence control unit is designed to maintain the voltage of the DC-capacitor of the back-to-back converter. Likewise, the negative-sequence and zero-sequence control units are expected to mitigate the imbalanced current components. A simple imbalanced LVDN is modeled and tested in Simulink/Matlab (MathWorks, US). The obtained results demonstrate the effectiveness of the proposed methodology.

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 PQ and Harmonic Assessment Issues on Low-Cost Smart Metering Platforms: A Case Study

Sensors ◽  
2020 ◽  
Vol 20 (21) ◽  
pp. 6361
Author(s):  
Giovanni Artale ◽  
Giuseppe Caravello ◽  
Antonio Cataliotti ◽  
Valentina Cosentino ◽  
Dario Di Cara ◽  
...  
Keyword(s):  
Power Quality ◽  
Feasibility Study ◽  
Low Voltage ◽  
Low Cost ◽  
Distribution Networks ◽  
Smart Metering ◽  
Energy Metering ◽  
Instrument Transformers ◽  
The Impact

This paper presents a feasibility study on how to implement power quality (PQ) metrics in a low-cost smart metering platform. The study is aimed at verifying the possibility of implementing PQ monitoring in distribution networks without replacing existing smart metering devices or adding new modules for PQ measurements, thus zeroing the installation costs. To this aim, an electronic board, currently used for remote energy metering, was chosen as a case study, specifically the STCOMET platform. Starting from the specifications of this device, the possibility of implementing power quality metrics is investigated in order to verify if compliance with standard requirements for PQ instruments can be obtained. Issues related to device features constraints are discussed; possible solutions and correction algorithms are presented and experimentally verified for different PQ metrics with a particular focus on harmonic analysis. The feasibility study takes into account both the use of on-board voltage and current transducers for low voltage applications and also the impact of external instrument transformers on measurement results.

scholarly journals Modeling of three-phase electric motor operation by the MATLAB system with deteriorated power quality in the 0.38 kV distribution networks

2018 ◽  
Vol 58 ◽  
pp. 03016 ◽  
Author(s):  
I.V Naumov ◽  
N.V. Savina ◽  
M.V. Shevchenko
Keyword(s):  
Induction Motor ◽  
Power Quality ◽  
Electric Motor ◽  
Distribution Networks ◽  
Negative Sequence ◽  
Operation Modes ◽  
Three Phase ◽  
Sequence Components ◽  
Motor Operation ◽  
The Impact

One of the main operation modes that characterizes power quality in distribution networks is asymmetry of three-phase voltage system. Operation of an induction motor (IM) with disturbed voltage symmetry in the supply network can not be considered as a rated one. The system of voltages applied to the stator winding of IM under these conditions contains positive- and negative-sequence components. This worsens the performance characteristics of IM essentially. In order to balance the 0.38 kV network operation and enhance the efficiency of the three-phase electric motor operation it is suggested to use a special balancing unit (BU) that minimizes the negative-sequence components of current and voltage. The operation modes of the obtained system “supply source – induction motor – balancing unit” are simulated within the MATLAB software package of applied programs, which allows one to assess the impact of low quality of power on the operating characteristics of the electric motor and the efficiency of the balancing unit to increase the “durability” of the motor under the asymmetrical power consumption.

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