Optimal Coordination of Overcurrent Relays in Power Systems Protection: A Review (original) (raw)

The user has requested enhancement of the downloaded file. All in-text references underlined in blue are added to the original document and are linked to publications on ResearchGate, letting you access and read them immediately. Abstract – Overcurrent relays (OCRs) are one of the most common protective devices implemented in power systems in order to protect the components from faults. In order to obtain a much improved protection by these protective devices, a precise coordination of these systems must be applied. One of the problems in power systems, which is very common, is that when a fault occurs in a system, two, three or even several OCRs operate instead of the designated relay to that particular fault location. This will result in power loss and disconnection of healthy lines out of the system which is extremely dire. To diminish or even abolish the extent of this catastrophe, OCRs must be well coordinated with each other. Many suggestions have been made and approaches implemented, however the most prominent method is the use of artificial intelligence (AI) to improve the function and coordination of OCRs in power systems. The most common and applicable software programs to do the simulation and for applying AI in relays are Matlab/Simulink and PSCAD/EMTDC. In this review paper, the best methods-with respect to reaching the optimal relay settings value to pave the way for coordination-are considered to be the genetic algorithm and the particle swarm optimisation technique. Keywords – overcurrent relay, overcurrent relay coordination, power systems protection, artificial intelligence, nature inspired algorithm, fault current limiter