19 research outputs found

    Calorimetric measurement and modelling of the equivalent series of capacitors

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    The equivalent series resistance of polypropylene capacitors has been determined under rated voltage, in the range 1 kHz–1 MHz, between 220 K and 370 K by a calorimetric technique. The original feature of this determination of capacitor losses lies in the use of the isothermal calorimetry and in the measurement of an electrical power and not of a temperature increase. The frequency dependence of the equivalent series resistance, at various temperatures, enables to separate the losses in the conducting material from those in the dielectric and to get their respective variations as a function of frequency and temperature. These variations of the equivalent series resistance with frequency at a given temperature have been reproduced by using an equivalent circuit composed of resistors, inductors and capacitors. This model has been verified for non-sinusoidal waveforms such as those met with in a filtering circuit and is used to evaluate by simulation the losses of the capacitor

    Approche dynamique du premier harmonique pour la modélisation de convertisseurs AC-AC à étage intermédiaire continu. Application aux générateurs à induction

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    In this paper, we present a modelling technique for power electronics converters with both DC and AC stages. This technique is based on a dynamical approach of the first harmonic method. The approach is first applied to an idealized converter and second is extended to a framework working under discontinuous conduction mode. At the end, comparative simulations are done to validate the continuous built model.Dans cet article, il est présenté une technique de modélisation de convertisseurs présentant à la fois des étages continus et alternatifs. Cette technique est basée sur une approche dynamique de la méthode du premier harmonique. La technique est tout d'abord appliquée à un convertisseur idéalisé pour être ensuite étendue à une structure travaillant en conclusion discontinue. En dernier lieu, des simulations viennent valider le modèle continu mis au point

    Current control of permanent magnet synchronous machines. Experimental and simulation study

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    Fault Tolerance on Interleaved inverter with Magnetic couplers

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    Abstract- The paper focuses on a new control strategy for improving the availability of power electronic converters based on interleaved structures. By using this strategy, the power electronic converters can continue to work (with reduced output power) in case of power component failure. The paper describes how to adapt the magnetic output filtering structure for this original control strategy. This structure is based on a monolithic coupler or a coupling transformer. Which are usually employed to minimize in a significant way the mass of the converters. They are normally sized to work with a fixed number of phases. Our control strategy induces new constraints on magnetic component, especially saturation problems. To reduce this problem some extra switch are added. Finally an experimental Power electronic converter driven by an FPG

    Modélisation grands signaux de convertisseurs à résonance série

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    The modelling of a resonant converter is quite difficult due to its periodic variable framework. The variation of its states implies a global nonlinear behavior. The model proposed in this paper is obtained by using the series expansion of the set of solution of the differential equations which describes the dynamic behavior of the converter. Once the method is introduced, it is applied to an example of a series resonant converter. Furthermore we show that the result can be extended to a family of converters. Experimental results are obtained and a comparison with the model actually in use is given. Finally, this model is applied to a stability analysis of this kind of converter.La modélisation des convertisseurs statiques à résonance est complexe car le circuit, de par sa topologie périodiquement modifiée au cours du fonctionnement, a un comportement global non linéaire. Le modèle proposé se base sur un développement harmonique à l'ordre supérieur au premier ordre, facile à mettre en œuvre et tenant compte du facteur d'amortissement du circuit oscillant. Ce modèle permet en outre l'étude dynamique du circuit. La méthode un fois introduite est appliquée sur un exemple de convertisseur à résonance série. A partir des résultats obtenus, le modèle est étendu à toute une classe de convertisseurs à résonance pour aboutir à un modèle général unique. Il est, par la suite, procédé à une validation expérimentale ainsi qu'à une comparaison avec le modèle classique du générateur de courant moyen équivalent. Cet article se termine par une application du modèle à l'analyse de la stabilité de ce type de convertisseur
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