Integration of feed back control in a field circuit coupled model

In this paper, we present a method accounting for feedback control in coupled field circuit models. This method can manage all kind of electronic switches which can be controlled by means of different electric or magnetic quantities calculated during the simulation (flux, currents, voltages,…). Electrical systems involving magnetic devices, power electronic converters and their control devices can be simulated in presence of phenomena such as eddy currents or saturation of the magnetic materials

DBD tranformerless power supplies: impact of the parasitic capacitances on the power transfer

A new transformerless power supply for DBD application is presented here. The power supply is built with 10kV SiC MOSFET. This high voltage switches allow holding the high voltage required by the DBD. An analytical study of the converter's operation is presented to deduce the power transmitted to the DBD. A comparison between the experimental and theoretical electrical waveforms is shown. The experimental waveforms are particularly affected by all the parasitic capacitances. When all the switches are in OFF state, oscillations cause over-voltages across the switches. An analysis of the effect of each capacitance is presented and demonstrates that the parasitic capacitances of the switches and of the inductance play a key role in the actual power transfer

Integration of control loops in coupled field circuit model to study magnetic devices supplied by power electronic converter and their control

In this paper, we present a method to take into account the feedback control in software developed from coupled field circuit models. The implementation of control loops is done in a software which is able to simulate electromagnetic devices associated with power electronic circuits having a time dependent topology. The control strategy is implemented in a discrete‐time version and can manage all controllable electronic switches by means of different electric or magnetic quantities calculated during the simulation (flux, currents, voltages, …). Electrical systems involving magnetic devices, power electronic converters and their control devices can be simulated in presence of phenomena such as eddy currents or saturation of the magnetic materials

Efficiency of an Exciplex DBD Lamp Excited Under Different Methods

Three different electrical generators have been designed and used to supply an exciplex dielectric barrier discharge lamp in order to elucidate the influence of each one of these supplying strategies over the system performance ; the first method consists on supplying the lamp with short bipolar voltage pulses; the second and third methods are based on semiresonant converters were current pulses, of controlled duration and magnitude, are injected into the lamp. For each one of the generators, measurements of the lamp and supply efficiency, are performed and analyzed, at different levels of power (up to 130 W) and operating frequencies (60–90 kHz). From the experimental results, the pulsed voltage-mode approach has allowed obtaining the highest lamp efficiency (7%), yet the maximum supply efficiency is offered by the resonant mode supplies. On the basis of the lamp and the supply efficiencies, the whole system performance is analyzed

Analytical input filter design in DC distributed power systems approach taking stability and quality criteria into account

This article presents an automated method for the sizing of filter parameters taking into account stability and quality criteria. The analytical linearized model of the system is automatically built from a circuit description. System stability conditions are firstly assessed on this model with the Routh-Hurwitz criterion. Then, filtering and damping conditions are introduced. To complete the sizing, optimization algorithms are introduced in order to minimize the energy stored in inductive and capacitive components. Simulations are performed on an embedded HVDC (High Voltage Direct Current) network onboard an aircraft (HVDC network); it associates several loads with their input filters, to validate the results obtained with the proposed method

Etude de qualité et de stabilité des réseaux aéronautiques embarqués HVDC

Dans le contexte du concept de l avion plus électrique , l électricité prend une part croissante dans les systèmes embarqués aéronautiques. Ainsi, de nombreuses évolutions ont eu lieu, concernant les réseaux de bord, notamment l architecture du réseau qui est devenue de plus en plus complexe, intégrant de nombreux équipements de différentes natures ; ceci entraîne de multiples questions relatives à la qualité et la stabilité du réseau. C est dans ce contexte que s inscrivent ces travaux de thèse, qui aboutissent d une part à la mise en œuvre de méthodes d analyse de la stabilité et de la qualité du réseau aéronautique embarqué et d autre part à l analyse de couplage entre plusieurs équipements connectés sur un seul réseau. Les études menées au cours de ces travaux reposent sur l utilisation des expressions analytiques représentant le comportement fréquentiel de réseaux continus. Une méthode de calcul basée sur les lois de la physique a été développée et validée par des approches de simulation et d expérimentation. Par ailleurs, en absence d un modèle analytique, nous choisissons de déterminer l'expression littérale du modèle équivalent du réseau à partir de l'identification des données issues de l approche expérimentale en se basant sur des algorithmes d'optimisation. Ces modèles analytiques sont associés aux critères mathématiques de stabilité (Routh-Hurwitz, MiddleBrook), et aux contraintes de qualité imposées par les standards aéronautiques, dans le but de dimensionner les éléments de filtrage à placer entre le réseau et l équipement. Le calcul des composants assurant le filtrage repose sur la recherche d une solution optimale : nous introduisons les algorithmes d optimisation utilisés en première étape, et nous proposons par la suite une formulation de la procédure de calcul des paramètres du filtre pour une meilleure illustration des résultats intéressants pour un concepteur de réseau. Enfin, nous clôturons ce travail par une analyse des couplages entre plusieurs équipements connectés sur un réseau continu et nous concluons par une approche expérimentale afin d appuyer les résultats théoriques.In the concept of the "more electric" aircraft, power takes an increasing proportion in aeronautic embedded systems. So many changes have occurred on board networks, including the network architecture that has become more and more complex, integrating many different types of equipment that causes quality and stability issues on the network. In this context that this thesis is inscribed, firstly it leads to the implementation of methods for stability and quality analyzing of the embedded network and secondly to coupling analysis of several devices connected to a single network. Studies conducted in this work are based on analytical expressions representing the frequency behavior of networks. A compute based on fundamental physical laws has been developed and validated by simulation and experimental approaches. Moreover, in the absence of an analytical model, we choose to determine the literal expression of the equivalent model of the network by identifying data, come from the experimental approach, using optimization algorithms. These analytical models are associated with mathematical criteria: Routh-Hurwitz, Middlebrook, and quality constraints imposed by aeronautic standards, in order to size the elements of the filter cell placed between the voltage source and the equipment to ensure the stability and quality of the entire system. The sizing of cell parameters based on optimal search by means of optimization algorithms in the first step, and then we propose a formulation of the calculation procedure of the filter parameters to illustrate some interesting results for designer s network. Finally, we close this work with a coupling analysis of several devices connected to a single DC bus and we conclude by an experimental approach to support the theoretical results.TOULOUSE-INP (315552154) / SudocSudocFranceF

Hybrid power generation system for aircraft electrical emergency network

A whole structure and two management strategies are proposed here for hybridisation of a Ram air turbine (RAT) by means of supercapacitors. Such hybrid structure is dedicated to an aircraft emergency network. The structure consists in coupling, through a 270 V DC bus, a controlled source (RAT) with a storage device interfaced through a bidirectional DC–DC converter. Both the energy-management strategies are described and analysed: the first one is to assign the ‘high-frequency harmonics’ of the load power to the storage which is current controlled, whereas the RAT controls the bus voltage and then only feeds the average power, losses and low-frequency harmonics of the load. The second one proposes an energy optimised operation of the system: the RAT, being current controlled, is able to maximise the supplied power (maximum power point tracking), as for classical wind turbines. For such a strategy, the bus voltage is regulated from the storage device. The RAT sizing and its mass can then be strongly reduced by means of this hybrid structure controlled with optimised management strategies. Experiments on a lab test-bench confirm analyses presented

Parametric study of dielectric barrier discharge excimer UV lamps supplied with controlled square current pulses

A parametric study of a system dedicated to non-coherent UV emission, by means of DBD excilamps, supplied by a controlled square shape current source is proposed. The presentation highlights on the one hand the performances experimentally obtained by combining together a set of 20 different bulbs with different diameters, gap and wall thicknesses (all the bulbs have the same length and are filled with the same Xe-Cl gas mixture), with different electrical power supplying conditions: magnitude, frequency (in the 30 kHz – 200 kHz range) and duty cycle of the square shape current pulses injected into the bulb. The performances concern the average UV power, the efficiency of the bulb conversion (electrical power to UV) and the adjustability of the power. On the second hand, we present design considerations of the power supply which has been especially developed for the purpose of these experiments

Design of a Current Converter for the Study of the UV Emission in DBD Excilamps

This paper presents the design of a current converter to supply a DBD exciplex lamp. The structure is implemented, based on a Boost converter. An analysis in the state plane is used, to determine the stability of the converter and the values of current and voltage during the discharge phase. An electrical model of the lamp is used to simulate the non measurable variables: the gas current and the gas conductance. Finally, the relationship between the gas current and the UV emission is presented

Alimentation électrique des dispositifs à décharge à barrière diélectrique (DBD)

L’utilisation d’une Décharge contrôlée par Barrière Diélectrique (DBD) permet d’obtenir un plasma froid à pression atmosphérique dont une des utilisations est le traitement de surface. Actuellement, de tels dispositifs sont alimentés par des sources de tension variable (amplitude, fréquence) : la décharge obtenue est le plus souvent filamentaire (défavorable à la qualité du traitement de surface), notamment lorsque l’on souhaite transmettre une puissance élevée. Des études récentes menées pour l’alimentation de lampes à excimères [1] ont montré l’intérêt de remplacer la source de tension par une source de courant, afin d’obtenir la décharge sur une plus grande plage de puissance et de fréquence, de disposer de degrés de liberté permettant le contrôle de la puissance transmise. Cet article est dédié à l’étude théorique et expérimentale d’une structure d’alimentation électrique de ce type