Nader Shojaei
Lorestan University

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Optimal Coordination of Overcurrent and Distance Relays Using Cuckoo Optimization Algorithm Farhad Namdari; Sajad Samadinasab; Nader Shojaei; Mohammad Bakhshipour
Indonesian Journal of Electrical Engineering and Computer Science Vol 16, No 3: December 2015
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/ijeecs.v16.i3.pp389-400

Abstract

The duty of protective systems is the timely detection of fault and removing it from the power network. The accuracy of the results and reducing the execution time of the optimizing algorithm are two crucial elements in selecting optimizing algorithms in protective functions. The most important protective elements that are used in power networks are distance and overcurrent relays. In this article, a new algorithm is presented to solve the optimization problem of coordination of overcurrent and distance relays by using Cuckoo Optimization Algorithm which considers the non-linear model overcurrent relays at all stages of setting. The proposed method is tested on a standard 8-bus power system network. Also the results obtained have been compared with other evolutionary algorithms. The results show that the proposed approach can be provide more effective and practical solutions to minimize the time function of the relays and achieving optimal coordination in comparison with previous studies on optimal coordination of overcurrent and distance relays in power system networks.
A Novel Protective Logic for Optimal Coordination of Overcurrent Relays Sajad Samadinasab; Farhad Namdari; Nader Shojaei
Indonesian Journal of Electrical Engineering and Computer Science Vol 16, No 3: December 2015
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/ijeecs.v16.i3.pp439-453

Abstract

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.