volv es calibrating the relays to the coordination cu rves and adjusting time dials to achieve specifi c op erating times. (4) When solid-state relay s are used, overtravel JEMT 6 (2018) 8-15 ISSN 2053-3535 Overcurrent relays coordination using MATLAB model A. Akhikpemelo1*, M. J. E. Evbogbai2 and M. S. Okundamiya3 1Department of Electrical and Electronic Engineering, Maritime Academy of Nigeria, Oron, Nigeria. Hence its time of operation is delayed by another CTI. Relay Coordination showing basic transformer protection scheme, It’s a predefined coordination time interval and it depends on the type of relays. 8 circuit breaker, relay over-travel time, relay tolerances, and a safety factor. A 0.355 margin is widely used i n field-tested systems employing very inverse and extremely inverse time overcurrent relays. breakers, and relays of various types, are quite sophisticated compared to the ones used 20 years ago. Relay-coordination-using-etap.pdf November 2019 143. Relay R 3 has to back up R 2. Coordination time interval (CTI) is the criteria to be considered for coordination. Ppt 5 Feeder Protection & Relay Coordination December 2019 49. time relays. Where no recommended time margins are available, a minimum margin of 0.35 second will be used. The protective device provides a form of insurance for high-cost electrical equipment. 2Department of Electrical and Electronic Engineering, Edo University, Iyamho, Edo State, Nigeria. A monitoring relay whose function is to limit the operation of associated protective relays to specific field protective relay A relay that functions to prevent overheating of the field excitation winding by reducing or interrupting the excitation of the shunt field. Relay coordination requires a time margin between the relay curves to account for interrupting time of the . Overcurrent Relay Coordination for Phase and Earth faults using ETAP Proceedings of 7 th IRF International Conference, 27 April-2014, Pune, India, ISBN: 978-93-84209-09-4 58 b. make sure that the relay farthest from the source has current settings equal to or less than the relays Relay R 1 does not have any coordination responsibility and hence it can trip without any intentional time delay. Coordination of distance and overcurrent relays using a mathematical optimization technique A dissertation submitted to the Electrical Engineering Graduate Program at the State Distribution Automation Handbook – Power System Protection Practice // Relay Coordination and Selective Protection – by ABB Further, the duration of the voltage dip caused by the short circuit fault will be shorter, the faster the protection operates. Protection of electrical power systems can reduce the extent and duration of an interruption, as well as reduce equipment damage or personal injury. A corrent relay co ordination can be achieved by any or all the following methods. Relay+coordination+methodology April 2020 23. 3Department of Electrical and Electronic … RELAY COORDINATION Coordination of relay is an integral part of the overall system protection and is absolutely necessary to isolate only the faulty areas and prevent tripping of healthy circuit. III. For electromagnetic relays, CTI is of the order of 0.3 to 0.4 s, while for a icroprocessor based relay, it is of the order of 0.1 to 0.2 s. To ensure reliability of the protective Relay Coordination Guidelines April 2020 22. See also: relay. Relay R 2 has to coordinate with relay R 1and hence its time of operation is delayed by time equal to Coordination Time Interval (CTI). More Documents from "Satya Vasu" Protection Setting Calculation in 2 hours 0. Relay Coordination (1) - Free download as Powerpoint Presentation (.ppt), PDF File (.pdf), Text File (.txt) or view presentation slides online. Relay Coordination