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Searching is a major activity in artificial Intelligence (AI). Evolutionary search and metaheuristic algorithms form major part of artificial intelligence that has been used to find optimal solutions to a variety of problems. They have been applied in various problems of electrical power systems like economic load dispatch and relay coordination. In this work their application to relay coordination...
This paper discusses a new approach to optimize overcurrent relay coordination in power distribution system by using a genetic algorithm. A modified objective function with constraints is taken to solve the relay coordination problem considering time setting and current setting multiplier. The result shows that the proposed method is fast, accurate and applicable compared to previous work proposed...
Overcurrent relays especially IDMT (Inverse Definite Minimum Time) relays are most commonly used protective device in the distribution system. It is vital that during abnormalities or faults, the IDMT overcurrent relay must be capable to isolate only the faulty part of power system from the healthy system. The operating time of IDMT relays can be reduced with proper coordination between primary and...
A simple but powerful optimization method for coordination of over current (OC) relays is presented in this paper. For distribution system protection as well as backup protection in transmission system, overcurrent relay is most widely used. Maloperation of relays may occur if primary and backup relays are not properly coordinated. And therefore relay coordination become important part of power system...
Application of modified Jaya algorithm for determining the optimum time multiplier setting (TMS) and plug setting (PS) of overcurrent relays (OCRs) is presented in this paper. The OCR time coordination is of great importance as it reduces the power outages by avoiding the backup relays to mal-operate. For this, the OCRs should have PS and TMS values set to their optimum values. Setting the PS and...
Protection system includes a series of devices whose main purpose is to protect people and primary electric power equipment from the effects of faults. Fault currents cause damage to equipment and are also hazardous to personnel. Thus, there should be a primary and a backup system with proper time grading between systems, i.e. Tripping time should be maximum for the point farthest from the fault location...
To reduce the damages due to the faults, protective system must have fast response. Fast isolation of faults necessitates minimum operating time of Over Current (OC) relays. Operating time of OC relays can be optimized by formulating the coordination problem as a Linear Programming Problem (LPP). Non Linear Programming Problem (NLP) of coordination can also be formed in which Time Multiplier Setting...
Optimization of over current relay settings is a major problem in protection of electrical power systems. This paper describes the Firefly algorithm for optimal time coordination of these relays. The algorithm has been implemented in MATLAB and tested on a radial system, as well as a single end fed system with a parallel feeder. The results obtained by the Firefly algorithm (FA) are compared with...
Penetration of Distributed generation (DG) in a distribution system changes the fault current and unidirectional nature of power flow. This leads to loss of coordination between various relays present in the system. This paper discusses formulation of the problem to determine optimal relay settings of an overcurrent relay with and without DG added to a system. A proper combination of primary and backup...
Coordination of overcurrent relays in a meshed distribution system is a challenge task for the protection engineers. Initially it was done manually. Linear and non-linear programming optimizing techniques are very frequently used for Coordination of overcurrent relays. Presently artificial intelligence is applied for optimal co-ordination of Overcurrent (OC) relays. This paper discusses application...
Directional over current relays (DOCRs) coordination problem is a nonlinear and nonconvex problem which has many constraints. Optimal coordination of over current relays has been usually solved using linear and nonlinear programming. Also genetic algorithm and particle swarm optimization methods are used to fined the optimal solution of the problem. In this paper a new hybrid approach will be used...
Several optimal coordination of overcurrent relays have been done in the past by using linear programming such as simplex, two-phase simplex and dual simplex and also intelligent optimization techniques such as genetic algorithm (GA) techniques. In this paper, a powerful optimal coordination method based on GA is introduced. The objective function (OF) is developed in a way that in addition to coordination...
Wireless mesh networks (WMN) must often be upgraded as usage demands evolve. This is usually done by adding gateways which serve to increase the backhaul capacity of the network. In this paper we study the problem of this type of capacity augmentation using free-space optical (FSO) backhaul links. A joint clustering and gateway placement problem is formulated which includes the strong rate-distance...
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