scholarly journals Improved Procedure for Earth Fault Loop Impedance Measurement in TN Low-Voltage Network

Energies ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 205
Author(s):  
Liviu Neamt ◽  
Alina Neamt ◽  
Olivian Chiver
Keyword(s):  
Modeling And Simulation ◽  
Complex Analysis ◽  
Low Voltage ◽  
Impedance Measurement ◽  
Distribution Networks ◽  
Measurement Procedure ◽  
Power Transformers ◽  
Earth Fault ◽  
Electrical Distribution Networks ◽  
Specialized Program

The difficulties and uncertainties related to earth fault loop impedance measurement are addressed in this paper. Based on the presentation of the measurement procedure implemented in the test equipment (diagrams and measured quantities, respectively, interpretation of results), the shortcomings and errors that accompany it are highlighted. The position in the power system, the influence of power transformers, and the use of effective quantities instead of phasors are important sources of errors, but, as will be seen, the switching of loads at the consumer sides and/or the occurrence of fault regimes during measurements can lead to the most serious impairment of the accuracy in the impedance assessment. The clarification of these aspects is achieved, both starting from the equivalent diagrams of the measurement circuits and the analytical interpretation of the phenomena associated with the measurements, as well as based on the modeling and simulation of TN low-voltage electrical distribution networks, in a specialized program, Eaton xSpider, which allows the complete and complex analysis of a large number of scenarios. Thus, essential conclusions were drawn regarding the level of errors and their causes, obviously, with the research coming with solutions to be implemented at the level of the measurement protocols of the devices used.

scholarly journals PENGARUH PEMBEBANAN TERHADAP NILAI RESISTANSI PENTANAHAN TRANSFORMATOR 250 KVA PADA GARDU BA 0005 PT. PLN (PERSERO) UP3 BENGKULU ULP TELUK SEGARA

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Dian Eka Putra
Keyword(s):  
Low Voltage ◽  
Electrical Energy ◽  
Distribution Networks ◽  
Grounding System ◽  
Grounding Resistance ◽  
Distribution Transformers ◽  
Measurement Results ◽  
Calculation Results ◽  
Electrical Distribution Networks ◽  
Resistance Value

             A distribution transformer as an electromagnetic device that converts and transfers electrical energy to the primary and secondary electrical distribution networks, is directly related to the ever changing load center. As a result of high loading and unbalance will cause an increase in neutral induced currents, of course, to anticipate changes in load that cause neutral phase currents in distribution transformers required grounding resistance values or low grounding in the neutral phase.The resistance value or grounding resistance according to the General Electrical Installation Requirements (PUIL) 2000 and SPLN3-1978 Regarding PLN Low Voltage Network Grounding and Installation Grounding does not exceed 5 ? or a maximum of 5 ?. The calculation results obtained the value of the grounding resistance in the neutral phase and the transformer body 250 KVA BA 0005 Distribution Substation, namely 4.11 ?. From these results it is necessary to have a comparative study of the resistance value from the calculation results with the value of the direct measurement results in the neutral phase grounding system and the 250 KVA transformer body BA 0005 Distribution Substation. From the results of direct measurements between 14.00 to 15.00 WIB with 50 percent loading on The transformer has the largest value of resistance in the neutral phase of 8.1 ? and on the transformer body of 8.3 ?. Keywords: 250 KVA Transformer, Grounding Resistance, Neutral Phase, Body Transformer

scholarly journals Method to determine fact and place of commercial losses in distribution networks

Vestnik IGEU ◽  
2021 ◽  
pp. 18-29
Author(s):  
I.M. Kazymov ◽  
B.S. Kompaneets
Keyword(s):  
Low Voltage ◽  
Electrical Engineering ◽  
Distribution Networks ◽  
Measuring System ◽  
Power Networks ◽  
Rigorous Results ◽  
Medium Voltage ◽  
Electric Power Networks ◽  
Unique Method ◽  
Electrical Distribution Networks

The improvement of methods to register the commercial losses in electrical distribution networks, and especially in low voltage networks, is one of the most important tasks for power supply providers. It is rather difficult to correctly register the fact of occurrence of such losses in the network. It is objectively impossible to analyze the state of the networks based on data obtained from various points of the specified network with the required accuracy. In this regard, at present no methods have been developed for remote detection of the fact and determination of the place of commercial losses in distribution networks, that could work in the mode of integration with automated information-measuring system of fiscal electricity metering. To solve this problem a method is to be developed that allows us to establish accurately for practical purposes the volume of commercial losses in the network and determine the place of their occurrence. During the research, methods of electric power networks modeling have been used. The assumption has been made about no flow of capacitive leakage currents to ground in the network, about full compliance of the line parameters with their calculated (nominal) values, as well as the basic laws of electrical engineering science. A unique method is proposed to determine the fact and the place of commercial losses in distribution networks. In contrast to the prototypes, it is based on the analysis of data obtained from metering devices, based on the key laws of electrical engineering and it allows us to get reliable arithmetically rigorous results without using fuzzy logic. The authors have proved theoretically and practically the effectiveness of the proposed solutions, and the possibility of their application. A calculation has been made to determine the place of commercial losses in the network using an example. The proposed method to determine the fact and place of commercial losses in distribution networks of low and medium voltage levels solves the problem of inability to effectively identify the points of occurrence of commercial losses in distribution networks. The reliability of the results obtained is confirmed by mathematical rigor of the method and algorithmic nature of the procedure for analyzing the distribution network.

scholarly journals Parameters of Insulation Relative to the Ground in Quarry Distribution Networks of Mining Enterprises in the Republic of Tajikistan

2021 ◽  
Vol 21 (1) ◽  
pp. 29-37
Keyword(s):  
Single Phase ◽  
Distribution Networks ◽  
Network Capacity ◽  
Life Safety ◽  
State University ◽  
Earth Fault ◽  
Electrical Distribution ◽  
Electrical Distribution Networks ◽  
The Republic

The article discusses a brief description of the mining enterprises of the Republic of Tajikistan, the insulation level of 6 kV quarry distribution networks. The parameters of network insulation relative to the ground are indicated as determined on the basis of the methods developed at the Department of Life Safety, South Ural State University. The performed calculations of insulation relative to the ground in quarry electrical distribution networks of mining enterprises in the Republic of Tajikistan showed that the value of the capacitive currents of a single-phase earth fault lies in the 0.1–0.37 A range and depends on the level of development of the enterprise. Considering the change in the network quiescence coefficient, the active insulation resistances of the network phases relative to the ground are in the 18–112 kΩ range. The network capacity relative to the ground is in the 0.09–0.34 µF range. The data obtained is necessary for selecting a security tool and evaluating the level of security.

scholarly journals Feasibility of Peer-to-Peer Energy Trading in Low Voltage Electrical Distribution Networks

2017 ◽  
Vol 105 ◽  
pp. 2227-2232 ◽  
Author(s):  
Chao Long ◽  
Jianzhong Wu ◽  
Chenghua Zhang ◽  
Meng Cheng ◽  
Ali Al-Wakeel
Keyword(s):  
Low Voltage ◽  
Distribution Networks ◽  
Peer To Peer ◽  
Energy Trading ◽  
Electrical Distribution ◽  
Electrical Distribution Networks

scholarly journals Software Solution for Modeling, Sizing, and Allocation of Active Power Filters in Distribution Networks

Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 133
Author(s):  
Dawid Buła ◽  
Dariusz Grabowski ◽  
Michał Lewandowski ◽  
Marcin Maciążek ◽  
Anna Piwowar
Keyword(s):  
Power Systems ◽  
Modeling And Simulation ◽  
Low Voltage ◽  
Harmonic Distortion ◽  
Distribution Networks ◽  
Active Power ◽  
Active Power Filters ◽  
Power Filters ◽  
Depth Analysis ◽  
Selection Of

The paper is related to the problem of modeling and optimizing power systems supplying, among others, nonlinear loads. A software solution that allows the modeling and simulation of power systems in the frequency domain as well as the sizing and allocation of active power filters has been developed and presented. The basic assumptions for the software development followed by the models of power system components and the optimization assumptions have been described in the paper. On the basis of an example of a low-voltage network, an analysis of the selection of the number and allocation of active power filters was carried out in terms of minimizing losses and investment costs under the assumed conditions for voltage total harmonic distortion (THD) coefficients in the network nodes. The presented examples show that the appropriate software allows for an in-depth analysis of possible solutions and, furthermore, the selection of the optimal one for a specific case, depending on the adopted limitations, expected effects, and investment costs. In addition, a very high computational efficiency of the adopted approach to modeling and simulation has been demonstrated, despite the use of (i) element models for which parameters depend on the operating point (named iterative elements), (ii) active filter models taking into account real harmonics reduction efficiency and power losses, and (iii) a brute force algorithm for optimization.

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.

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