Optimization of directional overcurrent relay times by particle swarm optimization

Abstract

An important problem in electrical engineering is to determine the optimal directional overcurrent relay times. The problem is modeled as a constrained nonlinear optimization problem in which the decision variables are the devices that control the act of isolation of faulty lines from the system without disturbing the healthy lines. Two models are considered namely IEEE-3 bus system and IEEE-4 bus system. The problem is solved using different versions of particle swarm optimization (PSO). The results obtained by PSO are compared with the results available in the literature. It is shown that PSO is able to provide superior results in terms of optimality and reliability in comparison to other methods. GENERAL FORM OF THE PROBLEMThe operating time (T) of a DOCR is non-linear function Manuscript

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“…(3): where α 0 is the initial randomness scaling factor, and δ is essentially a cooling factor. For most applications, we can use δ = 0.95 to 0.97 [11]. Regarding the initial α 0 , simulations show that FA will be more efficient if α 0 is associated with the scalings of design variables.…”

“…If the scaling variations are not significant, then we can set γ = O(1). For most applications, we can use the population size n = 15 to 100, though the best range is n = 25 to 40 [11] [12].…”

“…For example, particle swarm optimization was based on the swarming behavior of birds and fish [7], while the firefly algorithm was based on the flashing pattern of tropical fireflies [8] [9] and cuckoo search algorithm was inspired by the brood parasitism of some cuckoo species [10]. In the last two decades, more than a dozen new algorithms such as particle swarm optimization, differential evolution, bat algorithm, firefly algorithm and cuckoo search have appeared and they have shown great potential in solving tough engineering optimization problems [11] [12] [13] [14] [15] [16]. Among these new algorithms, it has been shown that firefly algorithm is very efficient in dealing with multimodal, global optimization problems.…”

Directional Overcurrent Relays Coordination Problems in Distributed Generation Systems

“…For each protection, only one coefficient is looked for, and the linear programming can be used. Other publications [24][25][26][27][28][29][30] have dealt with the determination of time multipliers M Oi and pickup currents I pcOi with predetermined slope. In the latter, the optimization is nonlinear and a more sophisticated optimization method must be used.…”

“…In the latter, the optimization is nonlinear and a more sophisticated optimization method must be used. However, all the aforementioned works [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] have mainly focused on the optimization process itself, but not much attention has been paid to choosing the proper short-circuit contributions types; additionally, only the maximum and minimum short-circuit contributions have been taken into account (and/or the current contributions values, without a calculation process description, have only been mentioned). As will be described in the article, the maximum and minimum short-circuit contributions can only be used if the short-circuit contributions flowing through primary and selective protections are the same.…”