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Number of results: 10
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Abstract

This paper presents a computationally efficient method for modelling an impact of the converter drive on the power grid. The formalized variable structure method (FVSM) allows for comprehensive studies of the effect on the power grid and examining the relation between this effect and the number of drive and feeding line parameters. In order to obtain a comprehensive model along with the model of the power grid, the parameters that are applied originate from a drive of a coal-fired power station. These parameters have been determined based on assessment and estimation. The estimation process was conducted with the aid of a model that allows for the commutation of power electronic elements. The authors confirmed that the model was correct by comparing empirical and theoretical voltage and current waveforms. Harmonic content of the voltage and current in the power grid which feeds the drive are considered to be the measure of the converter drive impact on the power grid. The standard method for the reduction of a harmonic content in the voltage and current involves the application of line reactors and distribution or converter transformers. As an example, the authors determine the impact of the drive on the power grid with respect to the adopted parameters of the line reactor. This example presents FVSM abilities with regard to simulation of complex systems that contain power grid components and converter drives.

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Authors and Affiliations

Ryszard Beniak
Arkadiusz Gardecki
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Abstract

The aim of the presented work was to examine the reliability assessment model on the example of a selected power grid object. The analyzed object was tested based on assumptions about technological breaks that were caused by overvoltage, among others. The study was conducted to check the reliability of integral elements of the power grid object and to assess the change in reliability level as a function of the frequency of inspections. The test results are to determine the optimal frequency of inspections of individual power grid objects in order to increase its reliability. In addition, the possibility of correlating optimal inspection periods resulting from the findings of this paper with periodic inspections of power network facilities was assessed.

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Authors and Affiliations

M. Borecki
M. Ciuba
Y. Kharchenko
Y. Khanas
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Abstract

The paper looks at the issues of operation safety of the national power grid and the characteristics

of the national power grid in the areas of transmission and distribution. The issues of

operation safety of the national transmission and distribution grid were discussed as well as threats

to operation safety and security of the electricity supply related to these grids. Failures in the

transmission and distribution grid in 2017, caused by extreme weather conditions such as: a violent

storm at the night of 11/12.08.2017, hurricane Ksawery on 5–8.10.2017, and hurricane Grzegorz on

29–30.10.2017, the effects of which affected tens of thousands of electricity consumers and led to

significant interruptions in the supply of electricity were presented. At present, the national power

(transmission and distribution) grid does not pose a threat to the operation safety and security of

the electricity supply, and is adapted to the current typical conditions of electricity demand and the

performance of tasks during a normal state of affairs, but locally may pose threats, especially in

extreme weather conditions. A potentially high threat to the operation safety of the national power

grid is closely linked to: age, technical condition and the degree of depletion of the transmission and

distribution grids, and their high failure rate due to weather anomalies. Therefore, it is necessary

to develop and modernize the 400 and 220 kV transmission grids, cross-border interconnections,

and the 110 kV distribution grid (especially in the area of large urban agglomerations), and the MV

distribution grid (especially in rural areas). The challenges faced by the transmission and distribution

grid operators within the scope of investment and operating activities, with a view to avoiding

or at least reducing the scale of grid failures in the case of future sudden high-intensity atmospheric

phenomena, are presented.

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Authors and Affiliations

Waldemar Dołęga
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Abstract

This paper provides a method for simplified description of a regional power grid model aimed to deliver a grid reduction, and improve grid performance observability. The derived power grid model can be used to analyze the regional allocation of the decentralized energy generation and consumption. The expansion of wind and solar generation in the power system affects the residual load. The power balance between electricity consumption and generation was calculated and analyzed based on the temporal and spatial scales. The proposed grid clustering method is a useful approach for performance analysis in systems with a growing share of renewable generation.
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Authors and Affiliations

Yang Li
1
ORCID: ORCID
Przemysław Janik
2
ORCID: ORCID
Harald Schwarz
1
Klaus Pfeiffer
1

  1. Brandenburg University of Technology Cottbus-Senftenberg, Department of Energy Distribution and High Voltage Engineering, 03046 Cottbus, Germany
  2. Wrocław University of Science and Technology, Department of Electrical Engineering Fundamentals, 50-377 Wrocław, Poland
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Abstract

Growing popularity of distributed generation is drawing special attention to communication technologies in smart power grids. This paper provides a detailed overview of the communication protocols utilized in the modern distributed grid laboratory. It describes both wired and wireless technologies used in Smart Grid and presents the remote operation of switching the subsystem from grid mode to island mode operating under nominal conditions. It shows the duration of power outages during a transfer to island mode with diesel generator running on idle - which simulates planned islanding and diesel generator stationary, which simulates unplanned islanding. Latency between registration of disturbance and executing control command is measured. The results obtained are compared with current legislation. The consequences to the power system that are possible in both scenarios are highlighted. Obtained results and description of the communication technologies can be useful for the design of distributed power grids, island-mode power grids, and Smart Grids, as well as for further research in the area of using combustion fuel generators as a primary power supply in the microgrid.
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Authors and Affiliations

Kamil Prokop
1
Andrzej Bień
1
Szymon Barczentewicz
1

  1. AGH University of Science and Technology, Kraków, Poland
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Abstract

The effectiveness of lightning protection on the power and distribution grid is a significant factor, which influences the power distribution reliability and the failure rate of system elements. As part of this article, a mathematical model will be presented, taking into account selected parameters that affect the assessment of the lightning hazard of an overhead line. The proposed model will consider the location of the object near the line and the adjustment of line conductor overhangs. Moreover, the mentioned mathematical model allows for analyzing the impact of considered parameters on the protection level of the power system, and transient overvoltages that occur in this system. The article contains also a detailed description of an effective and fast method to assess the lightning discharge impact on the power system with insufficient data. The introduced model was tested to verify the correctness of its operation by comparison of calculation results and functional data. High convergence of calculated and functional data and uncomplicated model structure ensure a wide range of applications for the proposed solution to easily prevent emergency situations in the power system. Furthermore, the described model gives the opportunity to assess the reduction of the range of selectivity zone associated with the power line, in conjunction with the impact of constructional peculiarities and a near object.

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Bibliography

  1.  J.L. He and R. Zeng, “Lightning shielding failure analysis of 1000 kV ultra-high voltage AC transmission line”, Proc. CIGRE Session, 2010, pp. 1‒9.
  2.  A. Borghetti, G. Martinez Figueiredo Ferraz, F. Napolitano, C.A. Nucci, A. Piantini, and F. Tossani, “Lightning protection of a multi- circuit HV-MV overhead line”, Electr. Power Syst. Res. 180, 1‒10 (2020).
  3.  A. Murphy, “Lightning strike direct effects”, Polymer Composites in the Aerospace Industry, 2nd Edition, Woodhead Publishing, 2020.
  4.  G. Shanqiang, W. Jian, W. Min, G. Juntian, Z. Chun, and L. Jian, “Study on lightning risk assessment and early warning for UHV DC transmission channel”, High Voltage 4(2), 144‒150 (2019).
  5.  R.G. Deshagoni, T. Auditore, R. Rayudu, and C.P. Moore, “Factors Determining the Effectiveness of a Wind Turbine Generator Lightning Protection System”, IEEE Trans. Ind. Appl 55(6), 6585‒6592 (2019).
  6.  J. Bendík, et al., “Experimental verification of material coefficient defining separation distance for external lightning protection system”, J. Electrostat. 98, 69‒74 (2019).
  7.  K. I. Pruslin, “Organization for increasing lightning resistance of overvoltage lines PJSC “FGC UES””, VI Russian Conference on Lightning Protection, 2018, pp. 1‒24.
  8.  G. E. Masin, “Indicators of lightning resistance of power facilities of Kubanenergo PJSC and measures to increase them”, VI Russian Conference on Lightning Protection, 2018, pp. 1‒9.
  9.  A. Andreotti, A. Pierno, and V.A. Rakov, “A new tool for calculation of lightning-induced voltages in power systems – ”Part I: Development of circuit model”, IEEE Trans. Power Del. 30(1), 326‒333 (2015).
  10.  C. Wooi, Z. Abul-Malek, M. Rohani, A. Yusof, S. Arshad, and A. Elgayar, “Comparison of lightning return stroke channel-base current models with measured lightning current”, Bull. EEI 8(4), 1478‒1488(2019).
  11.  T.H. Thang, Y. Baba, V.A. Rakov, and A. Piantini, “FDTD computation of lightning-induced voltages on multi-conductor lines with surge arresters and pole transformers”, IEEE Trans. Electromagn. Compat. 57(3), 442‒447(2015).
  12.  M. Brignone, F. Delfino, R. Procopio, M. Rossi, and F. Rachidi, “Evaluation of power system lightning performance Part I: Model and numerical solution using the PSCAD-EMTDC platform”, IEEE Trans. Electromagn. Compat. 59(1), 137‒145 (2017).
  13.  M.E.M. Rizk et al., “Protection Against Lightning-Induced Voltages: Transient Model for Points of Discontinuity on Multiconductor Overhead Line”, IEEE Trans. Electromagn. Compat. 62(4), 1209‒1218 (2020), doi: 10.1109/TEMC.2019.2940535.
  14.  J. Zhang et al., “Evaluation of the Lightning-Induced Voltages of Multiconductor Lines for Striking Cone-Shaped Mountain, ” IEEE Trans. Electromagn. Compat. 61(5), 1534‒1542 (2019).
  15.  Q. Li et al., “On the influence of the soil stratification and frequency-dependent parameters on lightning electromagnetic fields”, Electr. Power Syst. Res. 178, 1‒10(2020).
  16.  E. Soto and E. Perez, “Lightning-induced voltages on overhead lines over irregular terrains”, Electr. Power Syst. Res. 176, 105941 (2019).
  17.  M. Brignone, D. Mestriner, R. Procopio, M. Rossi, and F. Rachidi, “Evaluation of the mitigation effect of shield wires on lightning-induced overvoltages in MV distribution systems using statistical analysis”, IEEE Trans. Electromagn. Compat. 60(5), 1‒10 (2018).
  18.  M.R. Bank Tavakoli and B. Vahidi, “Shielding failure rate calculation by means of downward and upward lightning leader movement models: Effect of environmental conditions”, J. Electrostat. 68, 275‒283 (2010).
  19.  Y. Xu and M. Chen, “Striking Distance Calculation for Flat Ground and Lightning Rod by a 3D Self-Organized Leader Propagation Model”, Intern. Conf. on Lightning Protection, Vienna, Austria, 2012.
  20.  V. Cooray, C.A. Nucci, and F. Rachidi, “On the Possible Variation of the Lightning Striking Distance as Defined in the IEC Lightning Protection Standard as a Function of Structure Height”. Intern. Conf. on Lightning Protection, Vienna, Austria, 2012.
  21.  M.E.M. Rizk and G.N. Trinh, High voltage engineering, p. 804, Taylor and Francis Group, LLC, 2014.
  22.  Lightning protection guide. Dehn + Sohne GmbH + Co.KG., Germany, 2007/2012.
  23.  S. Takatoshi, “Lightning striking characteristics to tall structures”, IEEJ Trans. Electr. Electron. Eng. 13, 938‒947 (2017).
  24.  P.N. Mikropoulos and T.E. Tsovilis, “Striking Distance and Interception Probability, ” IEEE Trans. Power Delivery 23(3), 1571‒1580 (2008).
  25.  Y. Xie, M. Dong, H. He, J. He, H. Cai, and X. Chen, “A new tool for lightning performance assessment of overhead transmission lines”, Proc. 7th Asia-Pacific Int. Conf. Light., 2011, pp. 513‒519.
  26.  D. Spalek, “Proposal of the criterion for transmission line lumped parameters analysis”, Bull. Pol. Ac.: Tech. 67(6), 1181‒1186 (2019).
  27.  G. Benysek, M.P. Kazmierkowski, J. Popczyk, and R. Strzelecki, “Power electronic systems as a crucial part of Smart Grid infrastructure – a survey”, Bull. Pol. Ac.: Tech. 59(4), 455‒473 (2011).
  28.  S. Robak and R.M. Raczkowski, “Substations for offshore wind farms: a review from the perspective of the needs of the Polish wind energy”, Bull. Pol. Ac.: Tech. 66(4), 517‒528 (2018).
  29.  M. Borecki and J. Starzyński, “Selected Aspects of Numerical Models and Cost Comparison Analysis of Surge Protection Device”, Progress in Applied Electrical Engineering (PAEE), Poland, 2019, pp. 1‒4.
  30.  M. Borecki, M. Ciuba, Y. Kharchenko, and Y. Khanas, “Substation reliability evaluation in the context of the stability prediction of power grids”, Bull. Pol. Ac.: Tech. 68(4), 769‒776 (2020).
  31.  M. Borecki, “A Proposed New Approach for the Assessment of Selected Operating Conditions of the High Voltage Cable Line”, Energies 13, 5275(1‒15) (2020).
  32.  Z. Flisowski, Calculation of atmospheric surges in power lines based on antenna wave theory. Electrotechnical Dissertations, Volume XV, Z.1, pp. 177‒194, 1968.
  33.  M. Borecki, Analysis of atmospheric overvoltages protection of medium voltage overhead lines with covered conductors, pp. 1‒128, Warszawa, Wyd. P.W. 2017.
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Authors and Affiliations

Michał Borecki
1
ORCID: ORCID
Maciej Ciuba
1
Yevhen Kharchenko
2 3
Yuriy Khanas
3

  1. Warsaw University of Technology, ul. Koszykowa 75, 00-662 Warsaw, Poland
  2. University of Warmia and Mazury in Olsztyn, ul. M. Oczapowskiego 2, 10-719 Olsztyn, Poland
  3. Lviv Polytechnic National University, ul. S. Bandery St 12, 79000 Lviv, Ukraine
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Abstract

We introduce seven new versions of the Kirchhoff-Law-Johnson-(like)-Noise (KLJN) classical physical secure key exchange scheme and a new transient protocol for practically-perfect security. While these practical improvements offer progressively enhanced security and/or speed for non-ideal conditions, the fundamental physical laws providing the security remain the same.

In the "intelligent" KLJN (iKLJN) scheme, Alice and Bob utilize the fact that they exactly know not only their own resistor value but also the stochastic time function of their own noise, which they generate before feeding it into the loop. By using this extra information, they can reduce the duration of exchanging a single bit and in this way they achieve not only higher speed but also an enhanced security because Eve’s information will significantly be reduced due to smaller statistics.

In the "multiple" KLJN (MKLJN) system, Alice and Bob have publicly known identical sets of different resistors with a proper, publicly known truth table about the bit-interpretation of their combination. In this new situation, for Eve to succeed, it is not enough to find out which end has the higher resistor. Eve must exactly identify the actual resistor values at both sides.

In the "keyed" KLJN (KKLJN) system, by using secure communication with a formerly shared key, Alice and Bob share a proper time-dependent truth table for the bit-interpretation of the resistor situation for each secure bit exchange step during generating the next key. In this new situation, for Eve to succeed, it is not enough to find out the resistor values at the two ends. Eve must also know the former key.

The remaining four KLJN schemes are the combinations of the above protocols to synergically enhance the security properties. These are: the "intelligent-multiple" (iMKLJN), the "intelligent-keyed" (iKKLJN), the "keyed-multiple" (KMKLJN) and the "intelligent-keyed-multiple" (iKMKLJN) KLJN key exchange systems.

Finally, we introduce a new transient-protocol offering practically-perfect security without privacy amplification, which is not needed in practical applications but it is shown for the sake of ongoing discussions.

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Authors and Affiliations

Laszlo Bela Kish
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Abstract

A country’s “energy mix” typically evokes varying opinions among different groups within society. It also changes over time, at a pace that most energy consumers fail to appreciate. It is shifting even in Poland – certainly not a leader in the energy transition.
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Authors and Affiliations

Jan Kozłowski
1

  1. Institute of Environmental Sciences, Jagiellonian University in Kraków, Poland
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Abstract

The comprehensive evaluation of the smart grid is of great significance to the development of the power grid. This study mainly analyzed the coordinated planning of major networks and power distribution networks of the grid. Firstly, the coordinated planning of major networks and power distribution networks was introduced, then a comprehensive evaluation index system was established based on six domains, i.e., economy, safety, reliability, coordination, environmental protection, and automation. The evaluation of the indexes was realized through the expert scoring method. Finally, taking the power grid planning of Boao Town, Qionghai City, Hainan Province, China, as an example, the current scheme and planning scheme were evaluated. The results showed that the planning scheme had better performance in aspects such as economy and reliability, and its score was 15.39% higher than the current scheme, which verifies the effectiveness of the planning scheme and its feasible application in practical projects.
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Bibliography

[1] Perles A., Camilleri G., Croteau D., Principle and evaluation of a self-adaptive multi-agent system for state estimation of electrical distribution network, World Congress on Sustainable Technologies, London, UK (2016), DOI: 10.1109/WCST.2016.7886584.
[2] Erol-Kantarci M., Mouftah H.T., Energy-Efficient Information and Communication Infrastructures in the Smart Grid: A Survey on Interactions and Open Issues, IEEE Communications Surveys and Tutorials, vol. 17, no. 1, pp. 179–197 (2015).
[3] Sroka K., Złotecka D., The risk of large blackout failures in power systems, Archives of Electrical Engineering, vol. 68, no. 2, pp. 411–426 (2019).
[4] Liang F., Lv X., Liu J., ZhangW., Liu X.F., Gao B.T., Evaluation of investment projects on distribution network based on fuzzy algorithms, 2015 IEEE International Conference on CYBER Technology in Automation, Control, and Intelligent Systems (CYBER), Shenyang, China (2015), DOI: 10.1109/CYBER. 2015.7288038.
[5] Liu H.Q., Lin W.J., Li Y.C., Ultra-short-term wind power prediction based on copula function and bivariate EMD decomposition algorithm, Archives of Electrical Engineering, vol. 69, no. 2, pp. 271–286 (2020).
[6] An K., Liu H., Zhu H., Dong Z.Y., Hur K., Evaluation of conservation voltage reduction with analytic hierarchy process: a decision support framework in grid operations planning, Energies, vol. 9, no. 12, pp. 761–766 (2016).
[7] Wei Z.C., Zhao F.Z., Meng X.L., Song X.H., Ye Z.J., Sheng Y., Research on hierarchical evaluation index system of intelligent level in smart distribution grid, Advanced Materials Research, vol. 1092–1093, pp. 443–449 (2015).
[8] Cai B., Liu Y., Ma Y., Huang L., Liu Z., A framework for the reliability evaluation of grid-connected photovoltaic systems in the presence of intermittent faults, Energy, vol. 93, pp. 1308–1320 (2015).
[9] Xue M., Zhao B., Zhang X., Jiang Q., Integrated plan and evaluation of grid-connected microgrid, Automation of Electric Power Systems, vol. 39, no. 3, pp. 6–13 (2015).
[10] Azeroual M., Lamhamdi T., El Moussaoui H., El Markhi H., Intelligent energy management system of a smart microgrid using multiagent systems, Archives of Electrical Engineering, vol. 69, no. 1, pp. 23–38 (2020).
[11] Fadel E., Gungor V.C., Nassef L., Akkari N., Malik A., Almasri S., Akyildiz I.F., A survey on wireless sensor networks for smart grid, Computer Communications, vol. 71, no. NOV. 1, pp. 22–33 (2015).
[12] Bayindir R., Colak I., Fulli G., Demirtas K., Smart grid technologies and applications, Renewable and Sustainable Energy Reviews, vol. 66, no. DEC, pp. 499–516 (2016).
[13] Zhou X.S., Kong X.L., Ma Y.J., The Overview of Smart Grid, Applied Mechanics and Materials, vol. 552, pp. 103–106 (2014).
[14] He Y., Wu J., Ge Y., Li D.Z., Yan H.G., Research on Model and Method of Maturity Evaluation of Smart Grid Industry, International Conference on Life System Modeling and Simulation International Conference on Intelligent Computing for Sustainable Energy and Environment, vol. 763 (2017).
[15] Yang Z., Wu R., Yang J., Long K., You P., Economical Operation of Microgrid With Various Devices Via Distributed Optimization, IEEE Transactions on Smart Grid, vol. 7, no. 2, pp. 857–867 (2016).
[16] Li Y.B., Li Y., LiW.G., Application Credibility Theory in the Smart Grid Information Network Security Assessment, Advanced Materials Research, vol. 960–961, pp. 841–844 (2014).
[17] Vineetha C.P., Babu C.A., Smart grid challenges, issues and solutions, 2014 International Conference on Intelligent Green Building and Smart Grid (IGBSG), Taipei, Taiwan (2014), DOI: 10.1109/IGBSG. 2014.6835208.
[18] Ou Q., Zhen Y., Li X., Zhang Y., Zeng L., Application of Internet of Things in Smart Grid Power Transmission, IEEE 2012 Third FTRA International Conference on Mobile, Ubiquitous, and Intelligent Computing (MUSIC) – Vancouver, Canada (2012.06.26-2012.06.28) 2012 Third FTRA International Conference on Mobile, Ubiquitous, and Intelligent, pp. 96–100 (2012), DOI: 10.1109/MUSIC.2012.24.
[19] Chen P., Hu P., Selection of the Intelligent Power Distribution Cabinets for the Computer Room of Video Monitoring Data Center, Applied Mechanics and Materials, vol. 416–417, pp. 1076–1079 (2013).
[20] Strand J., Carson R.T., Navrud S., Ortiz-Bobea A., Vincent J., Using the Delphi method to value protection of the Amazon rainforest, Ecological Economics, vol. 131, pp. 475–484 (2017).
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Authors and Affiliations

Guangtao Ning
1
Bing Fang
1
Dan Qin
1
Yafeng Liang
1
Lijuan Zheng
2

  1. Power Grid Planning and Design Research Center, Hainan Power Grid Co., Ltd., China
  2. Tellhow Software Co., Ltd, China
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Abstract

Distributed generation is an issue intensively studied in recent years. It concerns, among others protection systems of distributed generation units connected to electric power grids. The main goal of this paper is to present the issue of functional reliability of selected passive loss of mains (LoM) protection systems, i.e. methods of detecting island operation in distribution power grids, which are implemented in PV inverters installed in sample MV and LV grids, typical for Polish conditions. First, different methods of detecting island operation have been distinguished and shortly characterized. Some problems concerning their action have also been presented. Then commonly used passive methods of island grid operation detection have been described. Next sample distribution grid has been presented and chosen disturbances modelled in the grid to test mentioned passive methods have been defined. For each of the determined type of disturbance the dynamic simulation has been carried out, as well as voltage and frequency plots for two selected RES nodes have been recorded and observed. All considered passive methods of island grid operation detection have been implemented in a Matlab/Simulink environment. Models of RoCoF, U/OVP and U/ OFP algorithms have been presented in diagrams. Then, results of carried out extensive studies have been shown in tables and discussed. The results are a consequence of a realized research project concerning electric grids in rural areas. Summary, final conclusions, and future research possibilities constitute the last part of the paper. The conclusions are mainly concentrated on evaluation of action of passive methods of island operation detection as well as possibility of using the methods in Polish conditions, particularly in rural distribution grids.

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Authors and Affiliations

M. Parol
M. Połecki

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