Evolutionäre Algorithmen

“…In order to assist with the choice of network parameters, a Genetic Algorithm (GA) has been employed to automatically investigate the parameter space for network creation (similar to the approaches in [23], [24]). For this sake, a GA Toolbox for MATLAB [19] has been used. The input values for the GA are the number of neurons in the hidden layers and the size of the training set.…”

Section: Ann Trainingmentioning

confidence: 99%

Neural Network Estimation of Generator Slot Fields for the Calculation of Radial Field Losses and Circulating Currents.

Schlemmer¹,

Streibkl²,

Müller³

2024

RE&PQJ

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In this paper, an approximate method for the fast calculation of magnetic fields inside the stator slots of large hydro generators is presented. Due to its relatively low computational cost, the approach is suitable for everyday use calculations in the process of tendering and design of hydro generators. The scheme comprises two parts. The first one is a Boundary Element Method (BEM) solution of a slot with current-carrying strands and ideally permeable walls. The second part consists in an Artificial Neural Network (ANN) for the incorporation of secondary effects, such as tooth saturation. The effects of induced eddy currents on the flux density at the strands' centres are taken into account by an iterative BEM solution with successive corrections of the resulting fields. Since eddy current effects are comparably small for the configurations usually applied, convergence is readily achieved. The training data for the ANN were obtained from a comparison between the linear BEM results and Finite Element (FE) computations which have been carried out on a set of 65 hydro generators at different slot temperatures. By employing the BEM approach, which captures most of the underlying physics, and a corrective neural network, a grey box model is obtained. This has the advantage that the output of the net is "safeguarded" by the BEM solution. In order to get a robust representation of the data, the training of the ANN was carried out applying a Genetic Algorithm (GA).

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“…Therefore, efficient search algorithms are needed, which probably makes use of chemical intuition to lower the search time. Various different optimization methods have been developed like Monte Carlo (MC), molecular dynamics (MD), and genetic algorithms (GAs) . Recently, a new algorithm has been proposed .…”

Section: Introductionmentioning

confidence: 99%

CAST: A new program package for the accurate characterization of large and flexible molecular systems

et al. 2014

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The presented program package, Conformational Analysis and Search Tool (CAST) allows the accurate treatment of large and flexible (macro) molecular systems. For the determination of thermally accessible minima CAST offers the newly developed TabuSearch algorithm, but algorithms such as Monte Carlo (MC), MC with minimization, and molecular dynamics are implemented as well. For the determination of reaction paths, CAST provides the PathOpt, the Nudge Elastic band, and the umbrella sampling approach. Access to free energies is possible through the free energy perturbation approach. Along with a number of standard force fields, a newly developed symmetry-adapted perturbation theory-based force field is included. Semiempirical computations are possible through DFTB+ and MOPAC interfaces. For calculations based on density functional theory, a Message Passing Interface (MPI) interface to the Graphics Processing Unit (GPU)-accelerated TeraChem program is available. The program is available on request.

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Evolutionäre Algorithmen

Cited by 43 publications

References 0 publications

Optimal placement of flat piezoceramic actuators for feedforward systems under the influence of real-time hardware delays

Optimal placement of flat piezoceramic actuators for feedforward systems under the influence of real-time hardware delays

Neural Network Estimation of Generator Slot Fields for the Calculation of Radial Field Losses and Circulating Currents.

CAST: A new program package for the accurate characterization of large and flexible molecular systems

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