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Journal articles on the topic 'Relays protection'
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1
Jurnal, Redaksi Tim. "STUDI METODE PENGGANTIAN RELAI MEKANIS MENJADI ELEKTRIS PANEL TEGANGAN MENENGAH PLTU UNIT 4 MUARA KARANG." Energi & Kelistrikan 9, no. 2 (November 23, 2018): 157–67. http://dx.doi.org/10.33322/energi.v9i2.47.
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Protective Relay is a device that provides alarm and trip / open signals to circuit breakers due to interference with protected equipment. Replacement of protection relay at the switchgear location of PLTU unit 4 Muara karang has been planned since 2010 and realized in December 2016 this coincides with Over Houl Mean Inspection. There are several problems encountered in the replacement of switchgear protection relays. The problem faced in performing this switchgear protective relay replacement is on mechanical relays that are replaced into electrical relays requiring many modifications and work steps. So in conducting this research is needed a proper method of research in order to produce a system of protection that is feasible operation
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Gurevich, Vladimir. "Susceptibility of modern relay protection: Will protection from cyber attacks help?" Serbian Journal of Electrical Engineering 11, no. 2 (2014): 233–41. http://dx.doi.org/10.2298/sjee131026019g.
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Modern trends in relay protection (RP) based on the substitution of electromechanical protection relays (EMPR) by digital protective relays (DPR) have resulted in the emergence of an absolutely new problem, which was not known before. This problem is the possibility of an intentional remote destructive impact (IRDI) on relay protection in order to put it out of action or make it perform functions that have nothing to do with the current operational mode of protected electric equipment. Traditional and well-known methods ensuring information safety cannot fully prevent unauthorized actions of RP. The article describes a new way for the problem solution.
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Goh, Hui Hwang, Sy yi Sim, Dahir Khere Diblawe, Mortar Mohamed Ali, Chin Wan Ling, Qing Shi Chua, and Kai Chen Goh. "Energy Power Plant in Electric Power Distribution Systems Equipping With Distance Protection." Indonesian Journal of Electrical Engineering and Computer Science 8, no. 1 (October 1, 2017): 192. http://dx.doi.org/10.11591/ijeecs.v8.i1.pp192-198.
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<p>This paper suggests the theory of distance protection criteria in power distribution systems for power plant generation. Multi-developed countries have energy power plants that placed in remote areas which are far from the grid line. Hence, they should be coupled to the low power transportation systems necessarily. While higher-rating relays are adopted to preserve feeders at power substations, fuses are merely obtainable outside on feeder channel. The safe system process, space protection is dispatched to save feeders. In this review, feeders with distance relays are equipped, together with over-current protection relays and fuses. Energy power plant having distance protection system is designed the implemented system was a 6-MW unit of compressed power energy reproduction. The sample feeder was shortened to be equal four-bus experiment feeder for transmitting resolution. The fault currents have chances adopted to form protecting regions of distance relays. Protection of the power line through the designed power plants for distance relaying can decrease problem in relay location because of the impedance-based location of the distance relay. </p>
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Sriram, Cholleti, and Y. Kusumalatha. "Three zone detection and distance relay co-ordination of power system protection." International Journal of Electrical and Computer Engineering (IJECE) 11, no. 2 (April 1, 2021): 919. http://dx.doi.org/10.11591/ijece.v11i2.pp919-928.
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To secure the transmission lines against power system faults, the distance relays are mostly used. Distance relay has its own Resistance (R)–Reactance (X) characteristics. Co-ordination of different distance relays is necessary for the fast operation of circuit breaker. Various distance relays which are being tripped with respect to circuit breakers which are attached at individual buses faraway from each other. These relays will be operated with respect to the distance between the occurred fault and relay location. In this paper, detection of three zones using relay characteristics, co-ordination of distance relays and circuit breakers are shown with the faults placed at different locations of an IEEE Nine bus system using MATLAB/Simulink GUI environment. A comparison also made between the relays performance and circuit breaker tripping operation with respect to severe faults at different locations on IEEE Nine bus system.
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Gurevich, Vladimir. "Hybrid reed: Solid-state devices are a new generation of protective relays." Serbian Journal of Electrical Engineering 4, no. 1 (2007): 85–94. http://dx.doi.org/10.2298/sjee0701085g.
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Research and development in the field of electromechanical protective relays has not been conducted for tens of years. Author?s approach allows viewing the problem of re-equipment of relay protection in a new way. In the author?s opinion combination of reed switches with magnetic circuits and semiconductor elements opens new avenues in development of the promising protective relays featuring reliability, simplicity and low cost. Examples of protective relays made with these elements are given below.
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Kamoona, Ameer Aqeel, Ahmed Najm alfadli, and Israa Ali Alshabeeb. "New Method for OC Relay Coordination." Journal of Electrical and Computer Engineering 2020 (May 13, 2020): 1–11. http://dx.doi.org/10.1155/2020/6312975.
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Protection relays design and manufacture have arrived to a new level of advancement; hence, numerical relays have appeared recently. They combine all the functions of monitoring, control, and protection in one device. Also these relays have the ability to communicate with each other to share statuses and orders using GOOSE (generic object‐oriented substation events) messages based on communication protocols such as IEC61850. In this paper, a proposed method for overcurrent (OC) relay coordination has been introduced based on numerical relay features of several setting groups and communication capability. This work supposes that the coordination between feeder, bus section, and incomer protection relays, in a substation of single busbar configuration with bus sectionalizer (i.e., bus section), depends on the status of the bus section circuit breaker (CB) as a criterion for determining active relay setting group, to achieve a faster tripping action. ETAP has been used as a simulation software environment. And the simulation results show the advantages of the proposed method in reducing the time needed by the relay to clear the electrical fault. Siemens SIPROTEC series have been used as an example of numerical relays, specifically 7SJ64 as OC relay, which exists in the ETAP library.
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Thararak, Panida, and Peerapol Jirapong. "Implementation of Optimal Protection Coordination for Microgrids with Distributed Generations Using Quaternary Protection Scheme." Journal of Electrical and Computer Engineering 2020 (February 13, 2020): 1–13. http://dx.doi.org/10.1155/2020/2568652.
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The flexible operation of microgrids, along with the availability of distributed generation (DG) units, causes a variety of changes in short-circuit current levels, magnitudes, and directions, which has undesirable effects on the operation of protection systems. Conventional protection schemes use typical directional overcurrent relays (DOCRs) with limited operating capability, unable to respond to microgrid operations in the manner of short-circuit current changes. In this paper, a quaternary protection scheme implemented with dual-directional overcurrent relays (dual-DOCR) and a protection control strategy is developed for protecting against faults in microgrids, taking into account the existence of DGs and connection and disconnection of DG units. The optimal dual-DOCRs setting and coordination are formulated as an optimization problem solved by evolutionary programming to minimize the relay operating times. The proposed protection scheme is implemented with a centralized protection control system based on the smart grid concept to increase the adaptability of the dual-DOCRs, which have multiple relay setting groups in accordance with system state changes. The simulation case studies are performed using the IEEE 14-bus test system, which is modified as a meshed microgrid operation. Test scenarios, including possible operations of microgrids, DGs availabilities, and different fault events, are analyzed and discussed. The comparative studies and simulation results show that the proposed scheme provides efficient coordination between the primary and backup relays and increases the responsibility of the protection system, which can be observed from the significant reduction in the relay operating times, resulting in the enhancement of selectivity, sensitivity, and speed of microgrid protection systems.
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Okorie, Patrick, Abdullahi Kunya, Yusuf Jibril, and Adam Abubakar. "Protection Coordination of Distribution Network with Optimally Placed Distribution Generation." ELEKTRIKA- Journal of Electrical Engineering 18, no. 3 (December 19, 2019): 13–20. http://dx.doi.org/10.11113/elektrika.v18n3.171.
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In this study, optimal distribution network protection coordination scheme with directional over current relays is developed. In addition, impact of optimally placed Distribution Generation (DG) on the protection coordination scheme is subsequently evaluated using relay Coordination Time Interval (CTI). As such, the study is carried out in two stages. In the first stage, optimal relays settings (time dial settings and pickup current) are determined. While in the second stage, the maximum DG penetration level with changes in the protection coordination is evaluated. Particle Swarm Optimization (PSO) algorithm, due to its faster convergence speed, is applied in both stages. The technique is implemented on the distribution section of the IEEE 14-bus and IEEE 30-bus systems and simulated in MATLAB. The simulation results obtained are compared with that obtained using hybrid Genetic Algorithm (GS) – Nonlinear Programming (NP) approach using relays pickup current and operating times as performance metrics. For the IEEE 14 bus system, the developed PSO-based relay coordination has reduced the relays pickup current and operating times by roughly 28% and 32% respectively compared with the hybrid GA-NLP technique. The optimal locations of the DGs are found to be bus 5, 8 and 12 which result in CTI of 0.233sec. While in the IEEE 30 bus system, the developed relay coordination has reduced the relays pickup current and operating times by roughly 31% and 34% respectively compared with the hybrid GA-NLP technique. Similarly, the optimal locations and sizes of the DGs are found to be bus 19, 26 and 30, which result in CTI of 0.462sec.
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Yang, Ming-Ta, and Li-Feng Chang. "Optimal Protection Coordination for Microgrid under Different Operating Modes." Mathematical Problems in Engineering 2013 (2013): 1–15. http://dx.doi.org/10.1155/2013/404086.
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Significant consequences result when a microgrid is connected to a distribution system. This study discusses the impacts of bolted three-phase faults and bolted single line-to-ground faults on the protection coordination of a distribution system connected by a microgrid which operates in utility-only mode or in grid-connected mode. The power system simulation software is used to build the test system. The linear programming method is applied to optimize the coordination of relays, and the relays coordination simulation software is used to verify if the coordination time intervals (CTIs) of the primary/backup relay pairs are adequate. In addition, this study also proposes a relays protection coordination strategy when the microgrid operates in islanding mode during a utility power outage. Because conventional CO/LCO relays are not capable of detecting high impedance fault, intelligent electrical device (IED) combined with wavelet transformer and neural network is proposed to accurately detect high impedance fault and identify the fault phase.
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Onah, Aniagboso John. "Investigating Phase Over-Current (OC) Protection in Medium-Voltage networks." European Journal of Engineering Research and Science 4, no. 6 (June 15, 2019): 41–49. http://dx.doi.org/10.24018/ejers.2019.4.6.1307.
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Overcurrent protection is protection against excessive currents or current beyond the acceptable current rating of equipment. It generally operates instantly. Short circuit is a type of overcurrent. Magnetic circuit breakers, fuses and overcurrent relays are commonly used to provide overcurrent protection. There is always a need to protect expensive power equipment. Protective relaying is a very important part of any electric power system that comes into play during trouble, fault or abnormal condition. The purpose is to isolate unhealthy part of electrical power system while the rest continue their normal operation. The entire electric power system from source to load centers is exposed and subject to natural hazards. The effects of these hazards are capable of interrupting normal operations of the system. Since these hazards cannot be prevented, precautions are taken to minimize or eliminate their effect on the system. The relay is a basic component of any protection scheme. The information (or signals) received from the power system actuates the relay, when necessary, to perform one or more switching actions. The signals are proportional to the magnitudes and phase angles of power system voltages and currents. When the relay receives these signals, it decides to close (or open) one or more sets of normally open (or closed) contacts, and consequently, the trip coil of a circuit breaker will be energized to open the power circuit. This paper investigates over-current relay protection scheme applied to medium-voltage electrical network. Methods of current and time grading have been applied in the coordination of the overcurrent relays in a radial network. Different time/current characteristics of relays such as the normal inverse (NI), very inverse (VI), and extreme inverse (EI) have been examined in order to obtain optimum discrimination.
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Nomikos, Nikolaos, Prodromos Makris, Dimitrios N. Skoutas, Demosthenes Vouyioukas, and Charalambos Skianis. "Wireless Femto-Relays." International Journal of Wireless Networks and Broadband Technologies 4, no. 1 (January 2015): 45–61. http://dx.doi.org/10.4018/ijwnbt.2015010104.
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The continuous increase in mobile data traffic creates the need for radical innovations in the mobile broadband system design. Heterogeneous networks (HetNets) deployment paradigm is an emerging research trend considered as the most significant aspect for meeting the mobile data challenge, mainly by proposing spectral efficiency enhancements and cell capacity gains from an overall system perspective. Two are the main challenges that dense small cell networks are facing: a) various types of interference mainly caused by unplanned deployments, and b) limited and Quality of Service (QoS)-unreliable wired backhaul links. In this paper, the authors propose a model where femtocells' and relays' complementary characteristics are effectively exploited into femto-relays. More specifically, the authors describe four main functionalities of this model: a) interference protection, b) two-fold backhaul alternatives (i.e. wired and wireless backhaul), c) opportunistic femto-relay selection, and d) full-duplex in-band relaying. To evaluate the anticipated technical impact of the proposed model, targeted simulation results are presented for a campus topology where femto-relays are compared with classic femtocells. Finally, related open issues, such as signaling overheads management, context-aware resource management, and business logic aspects are presented, with emphasis on the femto-relay's real market penetration opportunities in the mid and long-term future.
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Khoa, N. M., and D. D. Tung. "Modeling for Development of Simulation Tool: Impact of TCSC on Apparent Impedance Seen by Distance Relay." Engineering, Technology & Applied Science Research 8, no. 5 (October 13, 2018): 3332–37. http://dx.doi.org/10.48084/etasr.2199.
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The impact of thyristor controlled series capacitor (TCSC) on distance protection relays in transmission lines is analyzed in this paper. Voltage and current data are measured and collected at the relay locations to calculate the apparent impedance seen by distance protection relays in the different operating modes of the TCSC connected to the line. Short-circuit faults which occur at different locations on the power transmission line are considered in order to locate the fault for the purpose of evaluating the impact of TCSC on the distance protection relay. Matlab/Simulink simulation software is used to model the power transmission line with two sources at the two ends. Voltage source, transmission line, TCSC, voltage and current measurement, and discrete Fourier transform (DFT) blocks are integrated into the model. Simulation results show the impact of TCSC on the distance protection relay and determine the apparent impedance and fault location in the line.
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Radhi Mahmood, Jawad, Ramzy Salim Ali, and Raed A. Abd-Alhameed. "PLC/HMI-Based Implementation of a Real-Time Educational Power System Protective Relays Platform." Electronics 9, no. 1 (January 8, 2020): 118. http://dx.doi.org/10.3390/electronics9010118.
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Engineering laboratories are key elements in engineering learning and are essential for a concrete understanding of engineering topics and experiments. These key laboratories are no longer just hardware-dependent, they are a creative combination of programmable hardware and also user-defined driving software. In this work, an educational power system protective relaying laboratory platform was designed and implemented using a programmable logic controller (PLC) and human–machine interface (HMI) in order to introduce engineering students to the operating mechanisms experimentally. It engaged the students in selecting settings and upgrading the inverse definite minimum time (IDMT) protection relays for overcurrent, overvoltage, undervoltage, and differential current. With the platform and the help of the HMI, the students mastered (or came close to mastering) the field of protective relays, especially those explicitly implemented in the platform. The students were also able to see the real-time response that is equivalent to the relay operation time of the protective relays under the various possible settings, and the kinesthetic learning that was involved gave them a deeper understanding of what is involved in relays upgrading.
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Arzul, Ija Darmana, Erliwati, Adiv Rama Salvayer, and Tris Safri Yetno. "Analysis of Characteristics Over Current Relay and Ground Fault Relay on Feeder Rayon Tabing." MATEC Web of Conferences 248 (2018): 02006. http://dx.doi.org/10.1051/matecconf/201824802006.
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The reliability of power distribution of PT PLN (Persero) branch of Padang especially in Rayon Tabing most of the repeaters is still not optimal. This is due to an uncoordinated protection relay on each feeder. One effort made to improve the reliability of electric power is to rearrange the protection of overcurrent relays and ground disturbance relays on the feeder. So coordinated with each other well and is expected if there is interference in one of the repeater will not bring black out on other repeater. In this research we analyzed short circuit current at 20 kV side. From the analysis results obtained new relay protection settings based on the calculation of short-circuit current settings and compare the results with existing protection relays. By making efforts to improve the reliability of electric power is to rearrange the protection relay on each feeder. Based on short circuit current analysis on each repeater, the largest short circuit in 3 phase, 2 phase, and 1 phase disturbance is located at 1% disturbance location and the smallest disturbance is at 100% disturbance location. It can be concluded that the farther the location of the disturbance that occurs the smaller the disturbance, and vice versa, if the location of the disturbance that occurs closer then the greater the noise flow.
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Perdana, Iqbal Nusya. "Replacement of several single function generator protection relay at Badak LNG." MATEC Web of Conferences 277 (2019): 03008. http://dx.doi.org/10.1051/matecconf/201927703008.
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Badak LNG is a company that operates the largest LNG Plant in Indonesia with maximum production capacity of 22.5 MTPA. The company operates twelve (12) steam turbine generators and one gas turbine generator and one diesel engine generator to supply electricity for process, utility, storage, loading and plant support facility areas, which constitutes the criticality of power generator equipment to keep the reliability of production process. Generator protection relay is one of the equipment that monitors and protects the generator from fault resulting from either internal or external disturbance, preventing the generator from serious damages. Before 2015, Badak LNG used single function relays to protect the generators. The generators are protected by stator differential protection (87), current unbalance (46), loss of excitation (40), reverse power (32), time overcurrent with voltage restraint (51V), and time overcurrent ground (51G). These single function relays wield more disadvantages compared to the newer technology held by the digital relays. Since 2015, Badak LNG have started to replace the single function generator protection relays with the digital type ones.
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Sahebkar Farkhani, Jalal, Arsalan Najafi, Mohammad Zareein, Radu Godina, and Eduardo M. G. Rodrigues. "Impact of Recloser on Protecting Blind Areas of Distribution Network in the Presence of Distributed Generation." Applied Sciences 9, no. 23 (November 25, 2019): 5092. http://dx.doi.org/10.3390/app9235092.
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The protection relay issues increase with the penetration of distributed generation (DG) units in distribution networks. Blind protection, sympathetic tripping and failure of reclosing are the frequent problems that are created by adding DG to the distribution networks. This research focuses on the impact of reclosers on overcurrent relay blind protection areas with DGs embedded in the distribution network. The protection blinding in overcurrent relays leads to a delay or non-tripping of the relay. The conventional solution for the blinding issue is to increase the sensitivity in the relay settings. The variation of relay settings may cause problems in the distribution network. This paper investigates the effect of reclosers on eliminating blind areas and improves the reliability in the presence of DG. In this way, possible blind points of the case study are detected, and recloser relays are then installed in appropriate locations. The case study is based on realistic data of a distribution network. The DG consists of two generators with a capacity of 4 MW. The simulation is performed in DIgSILENT software.
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Gurevich, Vladimir. "Peculiarities of the relays intended for operating trip coils of the high-voltage circuit breakers." Serbian Journal of Electrical Engineering 4, no. 2 (2007): 223–37. http://dx.doi.org/10.2298/sjee0702223g.
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Parameters of the subminiature electromagnetic relays used as output elements in microprocessor relay protection, do not correspond to technical specifications on these relay protection. The reasons of this discrepancy are analyzed. Contradictions and discrepancies of the international standards in this area are considered. It is shown, that absence of clearness in standards and mistakes in technical specifications of manufacturers of microprocessor protection do not allow estimating correctly technical parameters and lead to decrease in reliability of relay protection.
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Nguyen, Thai-Thanh, Woon-Gyu Lee, Hak-Man Kim, and Hyung Yang. "Fault Analysis and Design of a Protection System for a Mesh Power System with a Co-Axial HTS Power Cable." Energies 13, no. 1 (January 2, 2020): 220. http://dx.doi.org/10.3390/en13010220.
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The uses of high-temperature superconducting (HTS) cables pose a challenge of power system protection since the impedance of the HTS cable is varied during fault conditions. The protection systems should be designed properly to ensure the reliability and stability of the whole system. This paper presents a fault analysis of the co-axial HTS cable in the mesh system and proposes a coordinated protection system. In the proposed protection system, the main protection is the differential current relay whereas the backup protections are the overcurrent and directional overcurrent relays. The normal and abnormal relay operations are considered to analyze the transient fault current in the HTS cable and evaluate the performance of the proposed coordinated protection system. Characteristics of cable impedances and temperatures under various fault conditions are presented. The proposed protection scheme is validated by the simulation in the PSCAD/EMTDC program. Simulation results show that the coordinated protection scheme could successfully protect the HTS cables in both normal and abnormal relay operations.
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Muljono, Agung Budi. "DISTANCE RELAY PROTECTION COORDINATION ANALYSIS OF HIGH VOLTAGE TRANSMISSION LINE 150 KV LOMBOK POWER SYSTEM." DIELEKTRIKA 7, no. 1 (February 27, 2020): 15. http://dx.doi.org/10.29303/dielektrika.v7i1.230.
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Lombok electrical system has been operating a 150kV high voltage transmission line and has been developing continuously. High voltage transmission line construction is an effort to improve electrical system quality and reliability. Thus, good protection is needed to maintain the distribution reliability of electrical power. One of the relays used in the Lombok electrical protection system is a distance relay. Distance relay works as the main protection in the transmission system by measuring fault impedance value based on current and voltage detected by the relay.
This study illustrates how to calculate distance relay setting impedance in Z1pri, Z2pri and Z3pri then held a short-circuit simulation in software ETAP 7.5 to examine it.
Setting calculation result of distance relay in Ampenan for Ampenan – Jeranjang line protection, with 3,25 Ω (7.543 km)line impedance, is Z1pri = 2.6057 Ω (6.0345 km), t1 = 0 second, Z2pri = 13.7056 Ω (31.7406 km), t2 = 0.4 second, Z3pri = 24.7209 Ω (57.2508 km), t3 = 1.2 second. Relay’s setting impedance is larger than fault impedance detected by the relay, so that distance relay has been able to protect the system. This study may also show graphic of setting impedance and time coordination from distance relay for every protection area section.
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Karupiah, S., M. H. Hussain, I. Musirin, and S. R. A. Rahim. "Prediction of overcurrent rRelay miscoordination time using artificial neural network." Indonesian Journal of Electrical Engineering and Computer Science 14, no. 1 (April 1, 2019): 319. http://dx.doi.org/10.11591/ijeecs.v14.i1.pp319-326.
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Overcurrent relay plays an important role in the protection of power system. For protection, proper coordination of relays with an appropriate relay settings need to be done. Coordination can be done by selecting an optimal Time Multiplier Setting (TMS) and Plug Setting (PS) considering the fault current at the relay location. Continuous Time Intervals (CTI) must be maintained between primary relay and secondary relay to ensure correct sequential operation of the relays. However, miscoordination can occurs due to secondary relay trips faster than primary relay. This paper presents an approach for predicting overcurrent relay miscoordination time using Artificial Neural Network (ANN) algorithm in MATLAB software. The efficiency of the proposed approach have been tested successfully on 17 bus test system. The simulation results indicated that the ANN Levenber-Maequardt algorithm is capable to predict the miscoordination time occurs between the primary and secondary relay operating time.
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Nagesh Kumar, G. V., B. Sravana Kumar, B. Venkateswara Rao, P. V. S. Sobhan, and K. Appala Naidu. "Linear programming technique based optimal relay coordination in a radial distribution system." International Journal of Engineering & Technology 7, no. 1.8 (February 9, 2018): 51. http://dx.doi.org/10.14419/ijet.v7i1.8.9450.
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Now-a-days to ensure power continuity and system’s reliability the protection system is to be designed properly for distribution systems to handle the faults to avoiding the damage to the equipments and to the service engineers. Different types of relays with different working principles are used to detect different types of faults in the system. In order to avoid mal operation of relays, proper coordination is to be carried out. The objective of this paper is to maintain the relay coordination as well as to decrease the working time of relays by optimizing the values of time dial setting (TDS) using linear programming problem technique (LPP). The inequality constraints guarantee the coordination margin for each primary or backup relay pairs having a fault very close to the primary relay. Simulation is carried out on a IEEE 15 bus balanced radial distribution system with 3 different types of relays namely standard inverse, extremely inverse and very inverse relay and the results are presented and analyzed.
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Samadinasab, Sajad, Farhad Namdari, and Nader Shojaei. "A Novel Protective Logic for Optimal Coordination of Overcurrent Relays." TELKOMNIKA Indonesian Journal of Electrical Engineering 16, no. 3 (December 1, 2015): 439. http://dx.doi.org/10.11591/tijee.v16i3.1634.
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Usually coordination of overcurrent relays is done by taking into account the specific structure of the system which does not show the real state of the system. On the other hand, dynamic changes in network can occur due to short circuit conditions, the malfunctioning relays, development, operation and repairs on any part of the power system. Also the most of the new protective schemes are based on a communication channel, which cannot be guaranteed in practice. Therefore, solving the problem of relay coordination is extremely difficult in case of dynamic changes in the network structure and the absence of communication links between some relays. In this article, a novel protective logic based on phasor measurement units (PMUs) data is proposed for optimal coordination of overcurrent relays. In this method, by using the PMU measurements, phasor information can be obtained continuously at any node where PMUs are installed in the power grid. For this purpose, in the first the Optimal PMU placement is determined for full network observability. Then, the dynamic changes of network will be observe by using wide area measurements based on PMUs data. Finally this information is sent via communication links PMUs for the optimal coordination of overcurrent relays. The use of PMU for the coordination of overcurrent relays improve the decision making capability and performance of protective relays and help them to form a reliable and robust protection system. The proposed method is tested on IEEE 8-bus and 14-bus standard networks.
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Irfan, Muhammad, Abdul Wadood, Tahir Khurshaid, Bakht Muhammad Khan, Ki-Chai Kim, Seung-Ryle Oh, and Sang-Bong Rhee. "An Optimized Adaptive Protection Scheme for Numerical and Directional Overcurrent Relay Coordination Using Harris Hawk Optimization." Energies 14, no. 18 (September 7, 2021): 5603. http://dx.doi.org/10.3390/en14185603.
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The relay coordination problem is of dire importance as it is critical to isolate the faulty portion in a timely way and thus ensure electrical network security and reliability. Meanwhile a relay protection optimization problem is highly constraint and complicated problem to be addressed. To fulfill this purpose, Harris Hawk Optimization (HHO) is adapted to solve the optimization problem for Directional Over-current Relays (DOCRs) and numerical relays. As it is inspired by the intelligent and collegial chasing and preying behavior of hawks for capturing the prey, it shows quite an impressive result for finding the global optimum values. Two decision variables; Time Dial Settings (TDS) and Plug Settings (PS) are chosen as the decision variables for minimization of overall operating time of relays. The proposed algorithm is implemented on three IEEE test systems. In comparison to other state-of-the-art nature inspired and traditional algorithms, the results demonstrate the superiority of HHO.
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Sauhats, Antans, Andrejs Utans, Gregory Pashnin, and Dmitrijs Antonovs. "Out-of-Step Relays Testing Procedure." Scientific Journal of Riga Technical University. Power and Electrical Engineering 28, no. 1 (January 1, 2011): 9–14. http://dx.doi.org/10.2478/v10144-011-0001-2.
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Out-of-Step Relays Testing ProcedureThe paper presents out-of-step (OOS) protection device testing methodology under close-to-real power system operation conditions. The power system stability modelling software is used as source of test signals. The accurate modelling of power system in conjunction with dynamical modelling features allows the correct choice of the most reliable OOS protection scheme. Methodology was applied for out-of-step relay "AGNA" testing and device settings verification.
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Zulkarnaini, Zulkarnaini, and Muhammad Rizki. "Study of Coordination on Protection Relay in High Voltage Transmission 150 kV (Payakumbuh – Koto Padang, West Sumatra)." MATEC Web of Conferences 215 (2018): 01021. http://dx.doi.org/10.1051/matecconf/201821501021.
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The disturbance of the high voltage transmission can be caused by a short circuit, overload, lightning surge, and other natural disturbances. That disturbance can lead to disruption of the distribution of electricity and damage to the electric power system installation equipment. A reliable protection system that can identify the disturbance quickly and also can securing affected parts of the system from other parts that can still operate normally are needed. Protection system operation may fail due to various factors; therefore, in addition to primary protection required backup protection that can work as primary protection fails to work. Distance relays can be used as primary protection as well as remote backup protection on high-voltage transmission. While overcurrent relay (OCR) and ground fault relay (GFR) is used as a local backup if distance relay failed to work. This research conducted a study of protection relays coordination for primary protection or backup protection on the high-voltage transmission that connects to Payakumbuh substation and Koto Panjang substation. Coordination is done by calculating the distance relay settings that use as primary protection as well as remote backup protection relay settings and calculating the overcurrent and ground fault relay that used as local backup protection. From the calculation, we get setting time to coordinate distance relay, overcurrent relay, and ground fault relay. Setting time was conducted to the first zone of the distance relay within 0 sec, and the second zone within 0.4 sec and third zone within 1.2 sec. For overcurrent relay and ground fault relay use time delay 1 second where the value is above the value that used in the second zone of distance relay. Distance relay can be coordinated with the auto-reclose relay to close the circuit breaker automatically sometime after a temporary disturbance. Setting that use to auto reclose relay is dead time 1 second and reclaim time 40 second. The coordination between the distance relay with auto-reclose relay can improve the quality of distribution of electrical energy.
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Kim, Joorak, Gyu-Jung Cho, and Jaewon Kim. "Development of Railway Protective Relay Simulator for Real-Time Applications." Applied Sciences 10, no. 1 (December 25, 2019): 191. http://dx.doi.org/10.3390/app10010191.
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Electric railways use a single-phase system, with the line comprising a trolley wire (TF) that supplies power to the load with a neutral wire and an autotransformer (AF) feeder to absorb the return current of the rail. Testing the performance of the protective relay that detects the fault of the traction power-supply system (TPSS) and operates the circuit breaker is very important. Until now, the performance test of protective relays for the TPSS has been conducted via a simple-steady test or using an expensive real-time simulator. However, under a fast-moving environment in which the load consumes a large amount of power, the protective relay must always detect faults and operate properly. This paper proposes a digital simulator that enables the dynamic testing of protective relays without using any steady test and expensive real-time simulators. This simulator includes both external waveform import and internal waveform generation functions. Users can test the operation of the protective relay by entering the waveform generated externally or internally into the protective relay. Additionally, it has the ability to monitor the operating protection elements and pickup time when the protective relay detects a fault and orders the circuit breaker trip.
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Setiawan, Eko, Septin Puji Astuti, and Handoko Handoko. "REDUCING THE LIKELIHOOD OF ELECTRICAL POWER-RELATED DISASTERS: A FUZZY MCDM APPROACH." Simetris: Jurnal Teknik Mesin, Elektro dan Ilmu Komputer 9, no. 1 (April 1, 2018): 679–86. http://dx.doi.org/10.24176/simet.v9i1.1761.
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Many of disasters are related to electrical power systems. They affect human life and economy. In order to reduce the negative impacts caused by the failure of electricity power system due to disasters and to create a robust electrical power system, selecting the best relay of electricity power is a must. This study identified the best protective relay of electrical power systems of PLN in Surakarta region by applying analytic hierarchy process (AHP), one of MCDM approaches, combined with fuzzy logic. Extent analysis approach was implemented to derive priorities of various criteria, sub-criteria and alternatives. Three relays being considered in the selection process are electromagnetic relay, digital relay and static relay. Four criteria in this study are techno-economy, fault frequency, protection of transmission line and advantage of relay over others. Meanwhile, five sub-criteria for each criterion are reliability, selectivity, sensitivity, working speed and efficient. Based on the criteria and sub-criteria, it can be inferred that in terms of four working areas of PLN management in Surakarta region, digital relay is seen as the best choice of relays.
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Kheshti, Mostafa, and Xiaoning Kang. "Optimal overcurrent relay coordination in distribution network based on Lightning Flash Algorithm." Engineering Computations 35, no. 3 (May 8, 2018): 1140–60. http://dx.doi.org/10.1108/ec-01-2017-0003.
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Purpose Distribution network protection is a complicated problem and mal-operation of the protective relays due to false settings make the operation of the network unreliable. Besides, obtaining proper settings could be very complicated. This paper aims to discuss an innovative evolutionary Lightning Flash Algorithm (LFA) which is developed for solving the relay coordination problems in distribution networks. The proposed method is inspired from the movements of cloud to ground lightning strikes in a thunderstorm phenomenon. LFA is applied on three case study systems including ring, interconnected and radial distribution networks. The power flow analysis is performed in Digsilent Power Factory software; then the collected data are sent to MATLAB software for optimization process. The proposed algorithm provides optimum time multiplier setting and plug setting of all digital overcurrent relays in each system. The results are compared with other methods such as particle swarm optimization and genetic algorithm. The result comparisons demonstrate that the proposed LFA can successfully obtain proper relay settings in distribution networks with faster speed of convergence and lower total operation time of relays. Also, it shows the superiority and effectiveness of this method against other algorithms. Design/methodology/approach A novel LFA is designed based on the movements of cloud to ground lightning strikes in a thunderstorm. This method is used to optimally adjust the time multiplier setting and plug setting of the relays in distribution system to provide a proper coordination scheme. Findings The proposed algorithm was tested on three case study systems, and the results were compared with other methods. The results confirmed that the proposed method could optimally adjust the relay settings in the electric distribution system to provide a proper protection scheme. Practical implications The practical implications can be conducted on distribution networks. The studies provided in this paper approve the practical application of the proposed method in providing proper relay protection in real power system. Originality/value This paper proposes a new evolutionary method derived from the movements of cloud to ground lightning strikes in thunderstorm. The proposed method can be used as an optimization toolbox to solve complex optimization problems in practical engineering systems.
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Solovev, Denis B. "Selection of Digital Filter for Microprocessor Protection Relays." International Journal of Electrical and Computer Engineering (IJECE) 8, no. 3 (June 1, 2018): 1498. http://dx.doi.org/10.11591/ijece.v8i3.pp1498-1512.
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The article considers some issues related to replacement of electromechanical relays used for protection of power facilities with microprocessor relays. One of the urgent problems connected with implementation of microprocessor overcurrent protections is how to use current transducers other than usual current transformers and in particular Rogowski coils that become more and more widespread. In the article are compared twelve methods of synthesis of a digital filter basing on the analog prototype – second-order integrating filter. The bilinear filter and Boxer-Thaler filters are analyzed in respect to their use in microprocessor relays. Basing on the research results a technique for selection of parameters of digital integrating filters for microprocessor relays is proposed. Simulation results show that Boxer-Thaler and bilinear filters have better accuracy during transient current measurements than the analog filter. The study allows concluding that in many cases the digital second-order bilinear filter is the best choice for use in microprocessor relays.
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Mei, Jun, Bin Liu, Jian Yong Zheng, and Lei Yao. "Study on a New Setting Method of Distance Relay with Superconducting Fault Current Limiter Adapt in the Grid." Advanced Materials Research 588-589 (November 2012): 471–74. http://dx.doi.org/10.4028/www.scientific.net/amr.588-589.471.
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Considerable attention is given towards developing Superconducting fault current limiter (SFCL) due to increasing short circuit levels in transmission lines, which itself imposes further changes on the measured impendence at the relaying point and causes significant impact on the lines’ relay protection, especially on the distance protection as the single-phase grounding fault occurs. In this paper, resistive superconducting fault current limiter connected to the grid is studied as the model to analysis how SFCL affects the grounded short-circuit impedance relay’s setting, then an new setting method of distance protection for the SFCL-equipped line is proposed. Finally, a power system model is built to analysis the theory by PSCAD / EMTDC simulation software. The results show that in the condition of using the impedance relays’ new setting method, impedance measurement error is greatly reduced, SFCL and line distance protection can work in coordination with each other properly.
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Mashar, Ali, Maula Zahara Firdausi, Achmad Mudawari, Achmad Deni Mulyadi, and Djafar Sodiq. "Design of Generator Stator Protection 100% Using Overvoltage and Undervoltage Schemes." Current Journal: International Journal Applied Technology Research 1, no. 1 (April 17, 2020): 66–80. http://dx.doi.org/10.35313/ijatr.v1i1.25.
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Nowadays, there are still many high capacity generators have not yet protected completely from their internal ground faults. They still rely on differential and over current relays. It is seen that this relay will reduce their sensitivities when applied to generators with high impedance grounding systems. To overcome such problem, a combination protection scheme of the neutral overvoltage (59N) and neutral undervoltage third harmonics (27N3) is developed. This paper aims to design the protection scheme for high capacity generators. This paper demonstrates the designing of neutral grounding transformer (NGT) system, the relay settings and reviewing of their sensitivities. To clarify the concepts this study uses a generator 802 MVA, 22.8 kV as object. The results show that the protection scheme is very effective to protect 100% of generator stator with relays overlapping of 31.5%. It needs NGT transformer with capacity of only 28.33 kVA, 15000/240 V, and the secondary resistor of 0.38,117 kW. This paper can hopefully be used as one reference for protection system engineers to design or develop protection schemes in their fields especially whose generator has not equipped yet with such protection scheme.
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Samuel, Anudevi, and Vinayak N. Shet. "Adaptive relay settings for distribution network with distributed generation (DG) using Sugeno fuzzy inference." International Journal of Emerging Electric Power Systems 22, no. 1 (December 25, 2020): 43–59. http://dx.doi.org/10.1515/ijeeps-2020-0152.
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Abstract The rapid increase in the power demand and the capacity shortage of transmission and distribution system drives the integration of Distributed Generation (DG) units in electrical power distribution networks. The integration of DG resources with distribution network can cause significant impacts in protection due to the bidirectional flow of current, particularly the changes in magnitude and direction of short circuit currents. It may also lead to false tripping or fail to trip the over current protection relays in the power system. The relay parameters have to adapt to the changes in the system to avoid unnecessary trippings. The proposed adaptive over current protection scheme, sets the parameters of the relays according to the changes in the network. This method determines the plug multiplier settings (PMS) and the time multiplier settings (TMS) using Sugeno Fuzzy Inference System (SFIS). The proposed methodology is tested for IEEE 13 bus system and 33 bus system and with the obtained adaptive relay settings, the validation for relay coordination is done using ETAP.
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Obied, Yamur M., and Thamir M. Abdul Wahhab. "Protection Coordination of 33/11 kV Power Distribution Substation in Iraq." Engineering and Technology Journal 39, no. 5A (May 25, 2021): 723–37. http://dx.doi.org/10.30684/etj.v39i5a.1790.
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The coordination between protective devices is the process of determining the most appropriate timing of power interruption during abnormal conditions in the power system. The aim of this work is to coordinate the protection of the 33/11 kV power distribution substation in Iraq using the CYME 7.1 software package. In this paper overcurrent and earth fault relays are simulated in two cases, with time delay setting and instantaneous setting, to obtain the Time Current Characteristics (TCC) curves for each Circuit Breaker (CB) relay of Al-Karama substation (2×31.5 MVA, 33/11 kV) in Babil distribution network. The short circuit current at each CB is calculated and accordingly, the protection coordination for Al-Karama substation has been simulated. The TCC curves have been obtained in two cases for overcurrent and earth fault relays; in a case with time delay setting and in the case with the instantaneous setting. The setting takes into consideration the short circuit current at the furthest point of the longest outgoing feeder and the shortest outgoing feeder.
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HORI, Masao, Tetsuo MATSUSHIMA, and Shogo MIURA. "100 years of Protection Relays." Journal of The Institute of Electrical Engineers of Japan 127, no. 6 (2007): 356–59. http://dx.doi.org/10.1541/ieejjournal.127.356.
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Bailey, B., and D. Jakominich. "Static relays permit enhanced protection." IEEE Industry Applications Magazine 5, no. 2 (1999): 10–17. http://dx.doi.org/10.1109/2943.750387.
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Vaithilingam, C., Himani Jain, Medha Ojha, Meghna Singh, and J. Vijay Joseph Samuel. "Adaptive protection scheme for microgrids." International Journal of Engineering & Technology 7, no. 2.31 (May 29, 2018): 37. http://dx.doi.org/10.14419/ijet.v7i2.31.13393.
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Micro grids are gaining attention to become an integral part of traditional power system, due to their numerous technical benefits and their ability to improve power system reliability.Voltage regulation, reduction in Transmission and distribution losses, reduction in the need for transmission capacity addition etc are the few technical benefits of micrgrids with renewable energy sources. However, a protection scheme that suits a conventional power system will require a major revamp if micro grids need to be interfaced. The power generations of each renewable source, mode of operation of microgrids are the few important factors to be considered to fix the relay settings. The conventional over current protection scheme faces selectivity and sensitivity issues during the grid faults and the microgrid faults, since the fault current level is different in both the cases. Hence, electro mechanical and static relays may not be suitable for the protection of power systems with microgrids. The processor based relays with augmented intelligence, that is, a relaying scheme which can act according to the operating condition need to be developed. This paper proposes an adaptive protection scheme for power systems with microgrids. The proposed method in this paper is tested with a hardware prototype resembles the actual microgrid setup.
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Morales, John, and Marco Carpio. "Induced Lightning Stroke Identification on Protection Relays." Applied Mechanics and Materials 775 (July 2015): 368–72. http://dx.doi.org/10.4028/www.scientific.net/amm.775.368.
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It is well known that lightning strokes produce mal-operation of transmission line protection relays. Where, protection devices cannot identify correctly between lightning stroke that generates or not permanent faults. Thus, when a flash produces a permanent fault, the protection relay sends a trip order, and the Transmission Line (TL) is disconnected correctly. However, when a lightning stroke does not produce a permanent fault, the protection devices also send the trip order, and the TL is disconnected unnecessary. In this context, these phenomena can produce unnecessary electric power outages, producing damage for the society and economic. Therefore, it is necessary to correctly identify between these lightning stroke signals. Besides that, direct lightning strokes, which hit directly on TLs or transmission towers, have usually been analyzed. However, induced lightning strokes, which hit on ground, have not been considered in previous analyzed. In this paper, in order to identify these induced lightning strokes, an algorithm based on a deterministic focus is proposed.
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Azriyenni, Azriyenni, and Mohd Wazir Mustafa. "Application of ANFIS for Distance Relay Protection in Transmission Line." International Journal of Electrical and Computer Engineering (IJECE) 5, no. 6 (December 1, 2015): 1311. http://dx.doi.org/10.11591/ijece.v5i6.pp1311-1318.
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The techniques hybrid intelligent was introduced in transmission protection that usage in electric power systems. There was applied ANFIS for distance relay protection particularly for transmission line. If a fault occurs during the transmission line identification caused by unwanted fault thus the power delivery to the consumer becomes not going well. Therefore, it would need to provide an alternative solution to fix this problem. The objective of this paper uses impedance transmission line to determine how long the channel spacing will be protected by distance relay. It has been distance relays when fault occurs in transmission line with the application Sugeno ANFIS. The simulation shows it excellent testing results can be contributed to an alternate algorithm that it has good performance to protecting system in transmission line. This application used by using software Matlab.
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Omorogiuwa, Eseosa, and Wonodi Ikonwa. "Distance Relay Protection Improvement of Alaoji-Afam 330kV Transmission Line." European Journal of Engineering Research and Science 3, no. 9 (September 30, 2018): 40. http://dx.doi.org/10.24018/ejers.2018.3.9.865.
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Fault resistance influences the operation of distance relays, thus causing it to give inaccurate impedance measurement, thus resulting to under-reach condition. .Trip report of fault occurrence in Alaoji-Afam 330kV line showed the effect of fault resistance on the relay operation. This paper seek to improve distance relay performance in terms of reliability, speed and selectivity on Alaoji-Afam 330kV transmission line, when fault resistance is present through adjustment of protected zone reach using NEPLAN software to model and simulate distance relay used for this study. Several simulations were run and the results showed good improvement of distance relay operation in handling fault conditions. Adjustment of the protected zone reach was done to compensate for the effect of high fault resistance on distance relay operation.
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Singh, Manohar, B. K. Panigrahi, and T. Vishnuvardhan. "Sympathetic Trippings Blocking in Over Current Relay Coordination Algorithm during Steady State & Transient Network Topologies." International Journal of Emerging Electric Power Systems 17, no. 3 (June 1, 2016): 311–26. http://dx.doi.org/10.1515/ijeeps-2016-0018.
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Abstract In this paper an improved over current relay coordination protection technique is proposed. The proposed technique eliminates the sympathetic/nuisance tripping in an interconnected distribution system. Nuisance trippings are eliminated by incorporating the additional selectivity constraints in conventional over current relay coordination problem. Whenever the fault is cleared only from one end of the line in bidirectional fault feed lines, transient network configuration comes into existence. Transient network configuration causes the redistribution of fault in the distribution system and leads to further nuisance tripping of relays. This problem in this paper is solved by minimising the operating time gap between primary relays located at near end and far end of a faulty line to the best minimum possible value. The differential search algorithm is applied for optimization of highly non-linear over current relay coordination problem in this paper. The result presented in this paper shows that the proposed over current relay coordination technique is immune against the sympathetic/nuisance tripping and operating time difference between primary relays at near end and far end is also minimised within acceptable time margin successfully.
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Osintsev, Anatoly A., Aleksandra I. Naumova, and Elena I. Gracheva. "Analysis of distance protection’s operation in cases of deep saturation of current transformers." E3S Web of Conferences 288 (2021): 01095. http://dx.doi.org/10.1051/e3sconf/202128801095.
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There is usually no information about permissible error of current transformers in modes succeed by large relative short-circuit current, at which microprocessor-based protections operate stably. By this reason, it is necessary to use data, defined for analog relays. It leads to value appreciation of a project because it is often essential to reduce current transformers’ error in case of a short circuit fault. Therefore, it is necessary to define the value of current transformers’ error, permitted for impedance relays. Conclusions of fundamental and applied sciences (mathematical analysis, theoretical foundations of electrical engineering, theory of simulation), analytical methods of researching nonlinear circuits and digital signal processing were used. A simulation model was created for setting overall tests of the current trans-former (CT) system. It was a relay protection device that reflected all the important properties of studied objects and allowed an analysis of digital distance protection’s operation at high levels of short-circuit currents. The factors influ-encing over digital distance protection’s operation in case of deep saturation of CTs were revealed, and a certain algorithm for definition of the permissible CT errors was proposed. Stable operation of digital distance protection was observed in case of a fault nearby the place of current transformers’ setting in all theoretically possible combinations of electrical system’s power and length of a protected electric power transmission line. It is valid if electric load choice is carried with account for stable protection’s operation in condition of a fault in the computational point and if voltage swell in secondary wirings is infeasible.
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Bhardwaj, Rahul Kumar. "Adaptive Differential Protection System for Microgrid." International Journal for Research in Applied Science and Engineering Technology 9, no. VII (July 25, 2021): 2364–71. http://dx.doi.org/10.22214/ijraset.2021.36880.
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Microgrids are the small version of power system which grants us the integration of distributed generation resources to insure the facilities to the remotely located electric loads as well as have so many advantages over traditional power system like reduced transmission loss, green energy solution and proper use of renewable energy resources. However the resilience offered by microgrid is inconvenient if it is not be able to protect properly in case of any disturbance occurs which is very common in microgrid due to load dynamics. Protective devices used in traditional power grid cannot actually protect microgrid due to variable loads and different fault levels at grid connected modes and islanded modes. The available research about this concern has not been very successful, therefore options like distance, directional over current and differential relay remains effective protection scheme from present standard. Even though these relays are very useful in power system but their effectiveness for microgrid is yet to be analyzed. This paper is presenting the MATLAB simulation based analysis for differential relay type adaptive protection system by taking a complex microgrid model and generating various fault and generation capacities and analyzing it. In this paper different scenarios has been discussed where differential relay seems to be better than distance and directional over current relay protection scheme.
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Ding, Pei, Fei Guo, Xu Tao Wu, Xiu Guang Li, Zhen Hua Yan, and Zhi Guo Hao. "New Development in Relay Protection for Smart Grid – Protection Function Development." Applied Mechanics and Materials 291-294 (February 2013): 2109–18. http://dx.doi.org/10.4028/www.scientific.net/amm.291-294.2109.
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The requirement is that the protection relay provides early warning for the protected device in order to guarantee the system reliability and high system security after fault is cleared. The development of new protection functions for smart grid is introduced in this paper. The principles and techniques of integrated state monitoring and main protection techniques for transformers are presented. The principles and techniques of transmission cross section protection which has developed from the line overload protection technique is also presented to show its application to avoid cascading overload tripping. Finally an islanding control system is presented. In the control system the islanding center is responsible for the co-ordination, and optimization and out-of-step relays are responsible for complimentary action. The aim of islanding control is that load-generation imbalance in each island is minimized and generators in each island are not out of step any more.
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Croft, S. A. "Protection relays and the EMC directive." Computer Standards & Interfaces 20, no. 6-7 (March 1999): 480. http://dx.doi.org/10.1016/s0920-5489(99)91077-2.
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Zamora, I., A. J. Mazón, V. Valverde, E. Torres, and A. Dysko. "Power Quality and Digital Protection Relays." Renewable Energy and Power Quality Journal 1, no. 02 (April 2004): 277–84. http://dx.doi.org/10.24084/repqj02.270.
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Calderaro, V., V. Galdi, A. Piccolo, and P. Siano. "Adaptive relays for overhead line protection." Electric Power Systems Research 77, no. 12 (October 2007): 1552–59. http://dx.doi.org/10.1016/j.epsr.2006.11.001.
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ABDELMOUMENE, Abdelkader, Rachid BOUDERBALA, and Hamid BENTARZI. "Design and Evaluation of a DSP Based Differential Relay of Power Transformer." Algerian Journal of Signals and Systems 1, no. 1 (February 2, 2021): 69–78. http://dx.doi.org/10.51485/ajss.v1i1.20.
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The problem of mal operation of differential protection of power transformer due to the inrush magnetizing current has long considered as a challenging problem. Several types of protection relays have been used to solve the issue (basic relay, percentage relay, multi slop ….). Each of them has its advantage and its limits. In this paper, a Digital differential relay has been developed and simulated. The logic used to distinguish between the inrush current and the internal fault is based on the theory of harmonic analysis. The behavior of the presented relay has been simulated versus various situations (inrush current, internal fault and external fault). The obtained results show that the proposed algorithm provides a good discrimination and a fast action.
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Sang, Zhongqing, Kai Yang, and Rencheng Zhang. "A security technology of power relay using edge computing." PLOS ONE 16, no. 9 (September 2, 2021): e0253428. http://dx.doi.org/10.1371/journal.pone.0253428.
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The purposes are to find the techniques suitable for the safety relay protection of intelligent substations and discuss the applicability of edge computing in relay protection. Regarding relay protection in intelligent substations, edge computing and optimized simulated annealing algorithm (OSAA) are combined innovatively to form an edge computing strategy. On this basis, an edge computing model is proposed based on relay fault traveling waves. Under different computing shunt tasks, OSAA can converge after about 1,100 iterations, and its computing time is relatively short. As the global optimal time delay reaches 0.5295, the corresponding computing time is 456.27s, apparently better than the linear search method. The proposed model can reduce the computing time significantly, playing an active role in the safe shunting of power relays. The simulation also finds that the voltage and current waveforms corresponding to the fault state of Phase A are consistent with the actual situations. To sum up, this model provides a reference for improving and optimizing intelligent substation relay protection.
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MATI, Ayache, Baadji BOUSAADIA, and Hamid BENTARZI. "A New Model of Numerical MHO Distance Relay Associated with Power Swing Detector." Algerian Journal of Signals and Systems 1, no. 2 (February 2, 2021): 121–28. http://dx.doi.org/10.51485/ajss.v1i2.26.
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In conventional transmission line protection, a distance relay is used to provide the primary as well as backup protection. The voltage and current phasors measurement needed by the distance relay for determining the impedance may be affected by the power disturbances such as power swing. Consequently, this power swing may cause mal-operation of Zone three distance relays which in turn may affect on the reliability of the whole protective scheme. Many power swing blocking functions (PSB) have been developed to mitigate these effects. In this paper, a new model of Mho distance relay with dual-quadrilateral power swing detection characteristic has been developed and implemented first in PC using LabVIEW, then tested using Power System Simulink Model under different faults and power swing conditions. Finally, the relay prototype has been realized using acquisition card NI USB-6009, which acquires real-time signals of the currents and the voltages, processes them digitally and outputs tripping or blocking signal to the circuit breaker. The obtained results show that the relay provides good discrimination between a fault and power swing condition.
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Abbasi, Ali, Hossein Kazemi Karegar, and Tohid Soleymani Aghdam. "Inter-trip links incorporated optimal protection coordination." International Journal of Electrical and Computer Engineering (IJECE) 10, no. 1 (February 1, 2020): 72. http://dx.doi.org/10.11591/ijece.v10i1.pp72-79.
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Due to advances in smart grid, different communication links as delay, inter-trip and activation are used between relays to enhance the protection system performance. In this paper, the effect of inter-trip links on optimal coordination of directional overcurrent relays (DOCRs) is analytically investigated and modelled. Moreover, an index is proposed to find the optimum locations for inter-trip link installation to reach the minimal fault clearance times under the selectivity constraint. Then a method is proposed to determine the candidate locations of inter-trip links and the associated reduced operating times. An Exhaustive search approach is also used to validate the efficiency of the proposed method. The method is simulated and tested on distribution network of IEEE 33 bus using the Power Factory software and MATLAB optimization toolbox. Genetic algorithm is used as an optimization tool to find optimal settings of relays. The results indicate the capability of proposed method in optimal protection coordination with optimum inter-trips.