Wyniki 1-4 spośród 4 dla zapytania: authorDesc:"Farid Benhamida"

Genetic Algorithm-Particle Swarm Optimization (GA-PSO) for Economic Load Dispatch

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This paper presents a method for Economic Load Dispatch (ELD). Economic dispatch problem is basically an optimization problem where objective function may be highly nonlinear, non-convex, and no differentiable and may have multiple local minima. Therefore classical optimization methods may be trapped to any local minima and may not be able to reach the global minima. The solution to this problem was presented by the application of heuristics methods such as genetic algorithms unfortunately the long execution time and non-guaranteed in convergence to the global optimal solution contribute the main disadvantages of GAs. In this paper provides a solution to this problem through a hybrid method Genetic algorithm - Particle Swarm Optimization (GA-PSO ) Streszczenie. Problem ekonomicznego rozsyłu energii ELD jest trudny do optymalizacji. Jedną z metod jest zastosowanie algorytmu genetycznego. Niestety algorytm ten jest czasochłonny i nie zawsze gwarantujący optymalne rozwiązanie. W pracy zaproponowano hybrydową metodę złożona z algorytmu genetycznego i algorytmu mrówkowego. (Hybrydowy algorytm genetyczny/mrówkowy jako metoda optymalizacji ekonomicznego rozsyłu energii) Keywords: economic load dispatch, genetic algorithm, particle swarm optimization. Słowa kluczowe: ekonomiczny rozsył energii, algorytm genetyczny, algorytm rówkowy. Introduction Economic Load Dispatch (ELD) are designed and operated to meet the continuous variation of power demand. The power demand is shared among the generating units and economic of operation is the main consideration in assigning the power to be generated by each generating units. Therefore, Economic load Dispatch (ELD) is implemented in order to ensure for economic operation of a power system. Economic Dispatch problem is an optimization problem that determines the optimal output of online generating units so as to meet the load demand with an objective to minimize the total generation cost [1]. Various [...]

Calculation of induced current in the objects placed in the vicinity of the high voltage transmission lines

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This paper gives a method of equivalent charge for calculate and represent the electric field around the three-phase lines and the current which will be induced in the objects near the high voltage transmission lines. In this present work, we establish a calculation program based on MATLAB in order to calculate and trace the induced current by the electric field under the lines. We can make simulation for several cases in order to establish some criteria which must be studied to evaluate safety and to make the provisions necessary to minimize the influence of electric field on the human body. Abstract. W artykule zaprezentowano metodę obliczeń pola elektrycznego w pobliżu linii trójfazowej oraz prądów indukowanych w obiektach w pobliżu linii przesyłowych wysokiego napięcia. W pracy wykorzystano oprogramowanie Matlab do obliczeń pola elektrycznego pod linią. Przeprowadzono symulację dla kilku typowych przypadków w celu ustalenia kryteriów umożliwiających ochronę człowieka przed generowanym polem elektrycznym. (Obliczenia prądów indukowanych w obiektach umieszczonych w pobliżu linii przesyłowej wysokiego napięcia). Keywords: Equivalent charge, Induced current, electric field, transmission lines, simulation. Słowa kluczowe: prądy indukowane, linie przesyłowe, pole elektryczne. Introduction For the design of High voltage lines, it is necessary to dimension these installations according to the high electric fields. The electric field at the industrial frequency is a phenomenon which exists around the electric power lines. It is increasingly high used which results in taking the consequences of this phenomenon in consideration. This subject proposes to the owner of these lines the replies to the problems raised by this constraint. It’s necessary to know the determination of electric fields, their calculation and their measurement, as well as the determination of the induced currents in the objects, including in living organisms by el[...]

Dynamic Economic Dispatch Solution with Practical Constraints Using a Recurrent neural network

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This paper proposes a solution to the dynamic economic dispatch (DED) with practical constraints using a Hopfield neural network (HNN). The constrained DED which will be solved in this paper must satisfy (i) the system load demand (ii) the spinning reserve capacity (iii) ramp rate limits and (iv) prohibited operating zone. The feasibility of the proposed HNN method is demonstrated using two power systems, and it is compared with the other methods in terms of solution quality and computation efficiency. Streszczenie. Artykuł proponuje rozwiązanie dynamicznej gospodarki przesyłem energii z uwzględnieniem ograniczeń przy wykorzystaniu sieci neuronowych Hopfield (HNN). Zaproponowana metoda została sprawdzona w dwóch systemach elektroenergetycznych i porównana z innymi metodami pod względem jakości i efektywności rozwiązań obliczeniowych. (Dynamiczne rozwiązanie gospodarki przesyłem energii przy wykorzystaniu sieci neuronowych) Keywords: dynamic economic dispatch, Hopfield Neural Network, prohibited operating zone, ramping rate limits. Słowa kluczowe: sieci neronowe Hoipfielda, gospodarka przesyłem energii. Introduction DED is used to determine the optimal schedule of generating outputs on-line so as to meet the load demand at the minimum operating cost under various system and operating constraints over the entire dispatch periods. DED is an extension of the conventional economic dispatch (ED) problem that takes into consideration the limits on the ramp rate of generating units to maintain the life of generation equipment [1, 2]. In general, the DED is solved by discretization of the entire dispatch period into a number of small time periods. Therefore, the static ED in each dispatch period is solved subject to the power balance constraints and generator operating limits. Previous efforts on solving static ED problems have employed various mathematical programming methods and optimization techniques ( lambda-iteration method, the base [...]

Solution of Inverse Problems in Electromagnetic NDT Using Neural Networks

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This paper presents a technique for solving inverse problems in electromagnetic nondestructive testing (NDT), using neural networks (NN). They are trained to approximate the mapping from the signal to the defect space. A crucial problem is signal inversion, wherein the defects profiles must be recovered from calculated signals by using finite element method (FEM), this method give good results by using the refinement mesh but in very long time. The idea of this paper is the exploitation of the FEM but with a middle mesh where the results are approached in short time. This signal was exploited in the inversion problem, where the maps represent the defects in the plate. The inversion results obtained with the NN are presented. The presented approach has permitted to realize good maps in a very reasonable training time with respect to others approaches. Streszczenie. Przedstawiono metodę rozwiązania odwrotnego z wykorzystaniem sieci neuronowych stosowanego w defektoskopii. Sieć jest trenowana na podstawie próbek z defektami. Pozwala to na stosowanie metody FEM ze znacznie mniejszą liczbą oczek. (Rozwiązanie problemu odwrotnego w defektoskopii elektromagnetycznej przy wykorzystaniu sieci neuronowych) Keywords: Eddy current, Finite element method, Defect characterization, Neural networks, Inverse problems. Słowa kluczowe: metoda prądów wirowych, defektoskopia, sieci neuronowe. Introduction In recent years the artificial neural network was to use in the nondestructive testing (NDT) where it’s interviewee to inverse problem. But, the NDT requires the use of the numerical analysis methods, among these methods, the finite element method (FEM). It appears to be very powerful because of its large flexibility which allows taking into consideration complex configurations [1]. Their application is widely used to detect cracks in metallic structures by using the Eddy currents [2]. This paper describes the inversion problem by using the neural[...]

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