scholarly journals Coordination of non‐directional overcurrent relays and fuses in active distribution networks considering reverse short‐circuit currents of DGs

2021 ◽  
Author(s):  
Mahdi Ghotbi‐Maleki ◽  
Reza Mohammadi Chabanloo ◽  
Mohammad Reza Taheri ◽  
Hatem H. Zeineldin
Keyword(s):  
Short Circuit ◽  
Distribution Networks ◽  
Overcurrent Relays ◽  
Short Circuit Currents ◽  
Active Distribution Networks

scholarly journals Alternative Methodology to Calculate the Directional Characteristic Settings of Directional Overcurrent Relays in Transmission and Distribution Networks

Energies ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3779 ◽  
Author(s):  
Jaramillo Serna ◽  
López-Lezama
Keyword(s):  
Optimization Problem ◽  
Operating Characteristic ◽  
Short Circuit ◽  
Distribution Networks ◽  
Directional Characteristic ◽  
Overcurrent Relays ◽  
Alternative Methodology ◽  
Transmission And Distribution

When addressing the problem of calculating the settings for directional overcurrent elements, the focus is usually the determination of the pickup, time dial and operating characteristic, in order to ensure proper selectivity with adjacent protection elements, thus limiting the problem related to the settings calculation of the direction determination characteristic to the application of typical settings and general guidelines, which cannot provide a reliable measure of the suitability of such settings. The present article describes in detail an alternative methodology for determining these settings, based on a characterization of the power system where the directional protection is to be applied, through the performance of a detailed short-circuit sensitivity analysis. From this, an optimization problem is formulated and solved to obtain the main settings shaping the direction determination characteristic, and then, a series of variables are used to measure the performance of the obtained settings, and even to improve it. The obtained results show the advantages of the application of the proposed methodology over the traditional methodology, based on typical settings and general guidelines, pointing out the risks of using the later.

scholarly journals Hybrid Harmony Search Algorithm Applied to the Optimal Coordination of Overcurrent Relays in Distribution Networks with Distributed Generation

2021 ◽  
Vol 11 (19) ◽  
pp. 9207
Author(s):  
Sergio D. Saldarriaga-Zuluaga ◽  
Jesús M. López-Lezama ◽  
Nicolás Muñoz-Galeano
Keyword(s):  
Distributed Generation ◽  
Search Algorithm ◽  
Short Circuit ◽  
Harmony Search ◽  
Distribution Networks ◽  
Harmony Search Algorithm ◽  
Small Scale ◽  
Coordination Problem ◽  
Overcurrent Relays ◽  
Optimal Coordination

In recent years, distributed generation (DG) has become more common in modern distribution networks (DNs). The presence of these small-scale generation units within a DN brings new challenges to protection engineers, since short-circuit currents tend to increase; additionally, as with microgrids, modern DNs may feature several operational modes depending on their topology and the availability of DG. This paper presents a methodology for the optimal coordination of overcurrent relays (OCRs) in modern DNs with a high presence of DG. Given the fact that protection coordination is a non-linear and non-convex optimization problem, a hybrid harmony search and simulated annealing (HS-SA) approach was implemented for its solution and compared against other techniques, such as conventional HS, genetic algorithm (GA), particle swarm optimization (PSO) and hybrid PSO-HS. Several tests were performed on a DN, considering different operative scenarios as a function of the DG available within the network. A comparison with other works reported in the specialized literature was carried out, evidencing the applicability and effectiveness of the HS-SA technique in solving the optimal OCR coordination problem in modern DNs.

scholarly journals Effect of Distributed Photovoltaic Generation on Short-Circuit Currents and Fault Detection in Distribution Networks: A Practical Case Study

2021 ◽  
Vol 11 (1) ◽  
pp. 405
Author(s):  
Daniel Alcala-Gonzalez ◽  
Eva Maria García del Toro ◽  
María Isabel Más-López ◽  
Santiago Pindado
Keyword(s):  
Renewable Energy ◽  
Radial Distribution ◽  
Short Circuit ◽  
Renewable Energy Sources ◽  
Distribution Network ◽  
Distribution Networks ◽  
Energy Sources ◽  
Protection Devices ◽  
Short Circuits ◽  
Short Circuit Currents

The increase in the installation of renewable energy sources in electrical systems has changed the power distribution networks, and a new scenario regarding protection devices has arisen. Distributed generation (DG) might produce artificial delays regarding the performance of protection devices when acting as a result of short-circuits. In this study, the preliminary research results carried out to analyze the effect of renewable energy sources (photovoltaic, wind generation, etc.) on the protection devices of a power grid are described. In order to study this problem in a well-defined scenario, a quite simple distribution network (similar to the ones present in rural areas) was selected. The distribution network was divided into three protection zones so that each of them had DG. In the Institute of Electrical and Electronic Engineers (IEEE) system 13 bus test feeder, the short-circuits with different levels of penetration were performed from 1 MVA to 3 MVA (that represent 25%, 50%, and 75% of the total load in the network). In the simulations carried out, it was observed that the installation of DG in this distribution network produced significant changes in the short-circuit currents, and the inadequate performance of the protection devices and the delay in their operating times (with differences of up to 180% in relation to the case without DG). The latter, that is, the impacts of photovoltaic DG on the reactions of protection devices in a radial distribution network, is the most relevant outcome of this work. These are the first results obtained from a research collaboration framework established by staff from ETSI Civil and the IDR/UPM Institute, to analyze the effect of renewable energy sources (as DG) on the protection devices of a radial distribution network.

scholarly journals Improvement of protection of distribution of sectioned lines with distributed generation sources (DGS)

2020 ◽  
pp. 67-77
Author(s):  
A. Omelchuk ◽  
◽  
S. Voloshchyn ◽  
L. Martyniuk ◽  
Yu. Kaidenko ◽  
...  
Keyword(s):  
Distributed Generation ◽  
Short Circuit ◽  
Relay Protection ◽  
Short Circuit Current ◽  
Distribution Networks ◽  
Distance Protection ◽  
Operating Modes ◽  
Maximum Current ◽  
Current Cutoff ◽  
Short Circuit Currents

When powered from a backup source, the short-circuit currents in the protected area are much lower than the current cutoff insert installed at the sectioning point, therefore, in this case, the current cutoff is ineffective. In cases where the maximum current directional protection (MCDP) does not provide the required sensitivity, it is advisable to use distance protection with dependent exposure on sectioned lines and lines from distributed generation sources (DGS) in a significant decrease in voltage on the DGS buses during external short circuits through a relatively large reactance of small and medium power. Different modes of operation of sectioned lines from DGS are characterized by a change in the direction of flow of the load current and short-circuit current. Therefore, on such lines, maximum current directional protections can be applied, which provide selective action of adjacent sets of line protection in different modes of their operation. The use of definite time protection leads to the accumulation of a long time delay for the protection installed on the main switch (especially when several sectioning switches are installed on the line), which complicates the coordination of the protection of the main sections of the lines from the protection of the supply substations. The article deals with the problems of improving relay protection for distribution networks with distributed generation sources (DGS). Paying attention to the peculiarities of protection operation under different operating modes of such networks, namely: normal and post-emergency. The protection of lines from DGS must meet the general requirements for ensuring the necessary sensitivity, selectivity of action for different types of damage. Difficulties in ensuring the required sensitivity when using overcurrent protection and current cutoff in such networks are caused by the low level of short-circuit currents from backup sources. The features of the implementation of relay protection in sectioned networks when they are powered from the DGS are given. The expediency of using remote triggering devices for distance protection to increase the sensitivity of protection of sectioned lines from DGS has been substantiated.

scholarly journals A Novel Machine Learning-Based Short-Circuit Current Prediction Method for Active Distribution Networks

Energies ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3793 ◽  
Author(s):  
Zheng ◽  
Wang ◽  
Jiang ◽  
He
Keyword(s):  
Distribution Systems ◽  
Large Scale ◽  
Short Circuit ◽  
Distribution Network ◽  
Prediction Method ◽  
Short Circuit Current ◽  
Distribution Networks ◽  
Test System ◽  
High Penetration ◽  
Active Distribution Networks

The traditional mechanism models used in short-circuit current calculations have shortcomings in terms of accuracy and speed for distribution systems with inverter-interfaced distributed generators (IIDGs). Faced with this issue, this paper proposes a novel data-driven short-circuit current prediction method for active distribution systems. This method can be used to accurately predict the short-circuit current flowing through a specified measurement point when a fault occurs at any position in the distribution network. By analyzing the features related to the short-circuit current in active distribution networks, feature combination is introduced to reflect the short-circuit current. Specifically, the short-circuit current where IIDGs are not connected into the system is treated as the key feature. The accuracy and efficiency of the proposed method are verified using the IEEE 34-node test system. The requirement of the sample sizes for distribution systems of different scale is further analyzed by using the additional IEEE 13-node and 69-node test systems. The applicability of the proposed method in large-scale distribution network with high penetration of IIDGs is verified as well.

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