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Design-oriented EMC analysis of wiring systems
Abstract
Modern aircraft hosts a large number of electric systems. Due to the transition to a More Electrical Aircraft, future platforms will use even more electric systems. This increases the complexity of the EWIS design from an EMC point of view. When possible, segregation between potentially interfering cables or bundles is a convenient solution to avoid EMC problems. Due to the huge number of installation configurations, the evaluation of the minimal segregation distance between two interacting bundles can be unfeasible. To overcome this situation, a specialized tool has been developed, based on a statistical approach for the analysis of the interaction between couples of bundles. In the paper, the different modules needed for this analysis are detailed and described. Some canonical analysis are then reported to show the capabilities of the tool.
... In this context, Safran Electrical & Power has initiated the CS2-ANALYST project (CFP07 GA 821128) with two Italian partners (IDS -Ingegneria Dei Sistemi and University of L'Aquila) and two French partners (AxesSim and ONERA). The objective of this project, as depicted in Fig. 1 is to implement a modeling tool [1] to evaluate within a reasonable time for a cable design team the optimum segregation distance, dopt, between two harnesses A and B connecting equipment, which will ensure the inter-compatibility considering the following inputs: The optimum segregation distance, dopt, must be valid for cable lengths l (identical for both routes) and for heights of harnesses hA and hB, varying in intervals specified by the enduser. This approach is conditioned by the fact that each harness, A or B, have been previously correctly constituted in terms of auto-compatibility which means that inside a harness, sources will not generate levels of currents and voltages larger than the susceptibility thresholds of neighbouring cables. ...
... Along with the induced currents, the G-parameter values are obtained through the function as given by (1). ...
Due to the large amount of electrical equipment aboard modern aircraft, several EMC problems appear which can be tackled by filtering disturbances at the equipment inputs and shielding cable links (braiding, covering, over-braiding). Among the others, the segregation between interfering cables or bundles of cables becomes crucial to ensure that coupling constraints will not exceed the equipment susceptibility threshold. The aim of this work is to statistically characterize the coupling between cable bundles and its minimization by optimization under stochastic constraints. The Monte Carlo method is used, and an interpolation scheme based on Smolyak grids is investigated to accelerate the computation.
This paper describes a specific methodology for modeling coupling on an aircraft Electrical Wiring Interconnection System (EWIS). The challenge is to be able to generate a model taking into account the required large number of cables, to organize the model with respect to the functional bundles and to maintain a reasonable computation time for the evaluation of the distribution of currents at the interface of equipment pieces. The methodology is tested on a representative test case at aircraft level.
We show how to enhance the performance of a Smolyak method for solving dynamic economic models. First, we propose a more efficient implementation of the Smolyak method for interpolation, namely, we show how to avoid costly evaluations of repeated basis functions in the conventional Smolyak formula. Second, we extend the Smolyak method to include anisotropic constructions that allow us to target higher quality of approximation in some dimensions than in others. Third, we show how to effectively adapt the Smolyak hypercube to a solution domain of a given economic model. Finally, we argue that in large-scale economic applications, a solution algorithm based on Smolyak interpolation has substantially lower expense when it uses derivative-free fixed-point iteration instead of standard time iteration. In the context of one- and multi-agent optimal growth models, we find that the proposed modifications to the conventional Smolyak method lead to substantial increases in accuracy and speed.
Due to the large amount of electrical equipment aboard modern aircraft, several EMC problems appear which can be tackled by filtering disturbances at the equipment inputs and shielding cable links (braiding, covering, over-braiding). Among the others, the segregation between interfering cables or bundles of cables becomes crucial to ensure that coupling constraints will not exceed the equipment susceptibility threshold. The aim of this work is to statistically characterize the coupling between cable bundles and its minimization by optimization under stochastic constraints. The Monte Carlo method is used, and an interpolation scheme based on Smolyak grids is investigated to accelerate the computation.
Due to the large amount of electrical equipment aboard modern aircraft, several EMC problems appear which can be tackled by filtering disturbances at the equipment inputs and shielding cable links (braiding, covering, over-braiding). Among the others, the segregation between interfering cables or bundles of cables becomes crucial to ensure that coupling constraints will not exceed the equipment susceptibility threshold. The aim of this work is to statistically characterize the coupling between cable bundles and its minimization by optimization under stochastic constraints. The Monte Carlo method is used, and an interpolation scheme based on Smolyak grids is investigated to accelerate the computation.
An important challenge in structural reliability is to keep to a minimum the number of calls to the numerical models. Engineering problems involve more and more complex computer codes and the evaluation of the probability of failure may require very time-consuming computations. Metamodels are used to reduce these computation times. To assess reliability, the most popular approach remains the numerous variants of response surfaces. Polynomial Chaos [1] and Support Vector Machine [2] are also possibilities and have gained considerations among researchers in the last decades. However, recently, Kriging, originated from geostatistics, have emerged in reliability analysis. Widespread in optimisation, Kriging has just started to appear in uncertainty propagation [3] and reliability and studies. It presents interesting characteristics such as exact interpolation and a local index of uncertainty on the prediction which can be used in active learning methods. The aim of this paper is to propose an iterative approach based on Monte Carlo Simulation and Kriging metamodel to assess the reliability of structures in a more efficient way. The method is called AK-MCS for Active learning reliability method combining Kriging and Monte Carlo Simulation. It is shown to be very efficient as the probability of failure obtained with AK-MCS is very accurate and this, for only a small number of calls to the performance function. Several examples from literature are performed to illustrate the methodology and to prove its efficiency particularly for problems dealing with high non-linearity, non-differentiability, non-convex and non-connex domains of failure and high dimensionality.
This paper describes an approved algorithm for the problems of unequal circle packing – the quasi-physical quasi-human algorithm. First, the quasi-physical approach for the general packing problems is described in solving the pure problems of unequal circle packing. The method is an analogy to the physical model in which a number of smooth cylinders are packed inside a container. A quasi-human strategy is then proposed to trigger a jump for a stuck object in order to get out of local minima. Our method has been tested in numerical experiments. The computational results are presented, showing the merits of the proposed method. Our algorithm can be thought as an adoptive algorithm of the Tabu search.
In this paper a novel approach is described for tree visualization using nested circles. The brother nodes at the same level are represented by externally tangent circles; the tree nodes at different levels are displayed by using 2D nested circles or 3D nested cylinders. A new layout algorithm for tree structure is described. It provides a good overview for large data sets. It is easy to see all the branches and leaves of the tree. The new method has been applied to the visualization of file systems.
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Available
at
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Kriging-based reliability assessment of structures submitted to fatigue
- echard
Echard, B.: Kriging-based reliability assessment of structures
submitted to fatigue. Ph.D. thesis, Université Blaise Pascal (2012).
CRIPTE : Code de réseaux de lignes de transmission multiconducteur -User's guide -Version 5.1" ONERA/DEMR/T-N119/10 -CRIPTE 5
- J P Parmantier
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J. P. Parmantier, S. Bertuol, and I. Junqua, "CRIPTE : Code de réseaux
de lignes de transmission multiconducteur -User's guide -Version
5.1" ONERA/DEMR/T-N119/10 -CRIPTE 5.1 2010
CRIPTE: Code de réseaux de lignes de transmission multiconducteur - User’s guide – Version 5.1
- J P Parmantier
- S Bertuol
- I Junqua
CRIPTE: Code de réseaux de lignes de transmission multiconducteur - User’s guide – Version 5.1
- parmantier
On the Analysis of General Multiconductor Transmission-Line Networks, Interaction Notes
- baum