This with the integration of distributed generation (DG) to meshed distribution systems, the operating time of the protective system becomes a major concern in order to avoid nuisance DG tripping. This paper proposes a new tripping characteristic for directional overcurrent relays (DOCRs) that can achieve a higher possible reduction of overall relays operating time in meshed distribution networ...

Abstract—Overcurrent (OC) relays are the major protection devices in a distribution system. The operating time of the OC relays are to be coordinated properly to avoid the mal-operation of the backup relays. The OC relay time coordination in ring fed distribution networks is a highly constrained optimization problem which can be stated as a linear programming problem (LPP). The purpose is to fi...

BACKGROUND: Distance protections are widely used in protection of energy transmission lines, but their time coordination is still an important and difficult problem. Inappropriate configuration leads to a hazard event: remote circuit breaker tripping provided the local circuit breaker can be opened, which severely impairs power system operation. OBJECTIVE: To describe a method and provide softw...

Deployment of relay nodes (RNs) in cellular orthogonal frequency division multiple access (OFDMA) systems provides an effective solution to increase high data rate coverage and improve cell throughput. However, a challenging issue is that additional interferences caused by RNs may substantially compromise the performance gain if no measure is taken. In this study, the authors address the proble...

Sharing a multiantenna relay among several sectors is a simple and cost-effective way to achieving much of the gains of local interference mitigation in cellular networks. Next generation wireless systems, such as ones based on the Third Generation Partnership Projects Long-Term Evolution Advanced, will employ universal frequency reuse to simplify network deployment. This strategy is anticipate...

This paper concerns two-hop communication over relay-assisted Block fading channel. It is assumed there is not a direct link between the transmitter and the affiliated destination and the communication occurs in two hops through the use of a relay, where the amplify and forward (AF) strategy is employed at this node. In this case, in a Rayleigh block fading channel, the optimal weight function ...

Electric power distribution networks are generally radial in nature, with unidirectional flows transmitted from the highest voltage levels to consumption levels. The protection system these is relatively simple and consists mainly of fuses, reclosers (RC) overcurrent relays (OCRs). installation distributed generation (DG) a network causes coordination problems between devices, because no longer...

Particle Swarm Optimization, a recently more popular optimizer utilizes the swarm behavior in searching for an optimum. The classical/standard PSO (SPSO) algorithm is normally used for unconstrained optimization tasks. The Directional Over-Current Relay (DOCR) Coordination problem is a highly constrained optimization problem, therefore the SPSO in its original form cannot be used to solve it. T...