Optimal Matching Between a Permanent Magnet Synchronous Machine and a Wind Turbine – Statistical Approach

International audiencehis paper proposes a methodology to decide the optimal matching between the size of the rotor of a wind turbine and the rated power of a permanent magnet synchronous machine. This is made taking into account the average electrical energy produced over a period of time. The analytical model of the wind energy conversion system is used to calculate the output power curve. The influence of the number of pairs of poles over the average power is also studied

SISTEMAS DE CONVERSIÓN DE ENERGÍA EÓLICA CONTROL Y DISEÑO

International audienceEste artículo aborda algunas de las soluciones actuales más utilizadas de los sistemas de generación eólica, enfatizando en los fundamentos del control y el diseño de aplicaciones individuales de potencia reducida. Lo previo, orientado a pequeños sistemas de potencia rurales o aislados, donde la conexión a la red pública es difícil o muy costosa. Se examinan los elementos en común y diferencias de las diversas propuestas existentes, ventajas y desventajas, su potencial y lo que se puede esperar de sus tendencias en el mediano y largo plazo

Analytical Calculation of Rotor Magnet Eddy-Current Losses for High Speed IPMSM

International audienceFor high-speed machines applications, eddy-current losses in the interior permanent magnet of synchronous machine (IPMSM) form a portion of the total losses which can be significant. Indeed, the magnets are exposed to the harmonic fields which rotate with respect to the rotor. The induced losses in the magnets provoke temperature arising that must be limited to avoid the risk of demagnetization. The study carries out a prediction of eddy current losses in PM where the skin effect is considered. A complete analytical model is presented and compared to 3D Finite Element (FE) harmonic computations. The results given by the proposed model are in agreement with the FEA results for local electromagnetic quantities and loss calculations. This approach can be useful for losses estimation in magnets when designing machines by analytical method

Design and sizing of electromagnetic linear actuators for valve applications

International audienceIn this paper, various structures of linear motion actuators are described. These structures have been studied in order to drive the valves of a car motor. According to general specifications, a description of the design and sizing of variable reluctance or permanent magnet devices is given. The main qualities of each structure are enhanced

Magnetic Losses Evaluation in PM SM Drive with Non Sinusoidal Supply by Finite Elements Analysis and Superposition

International audienceField superposition in rotating machines with sinusoidal distribution of magneto motive force and non sinusoidal voltage supply is analyzed in view of specific behavior of field components rotating in opposite direction at the same velocity in relation to rotor. These components – 5th and 7th, or 11th and 13th etc – form oscillating fields which imply rotor losses quite different than it is usually expected in superposition procedures, where overall losses are given by sum of effects produced by individual harmonic components of sliding fields. In case of eddy current losses in rotor's permanent magnets the difference for one pair of harmonics can reach several tens per cent

Magnetic Lossess Simulation in PM SM Drive by FE: Harmonic Superposition by Method of Locked Rotor

International audienceThe PWM-supplied permanent magnet synchronous machines are exposed to magnets' heating due to harmonic fields which rotate in relation to rotor. The corresponding losses can be calculated by FE simulation for each frequency, with superposition of all components of the losses. In certain conditions three dimensional modelling is required to get enough precision. However, time-stepping 3D finite element methods coupled with motion equations can lead to excessive computational time. Then a locked rotor approach with current sheet rotating may be interesting. In this case however, the superposition doesn't really work unless special procedure is applied. Magnetic loss dissipation cannot be correctly calculated with simple superposition of individual fields, e.g. the 5th and 7th harmonic rotating in opposite direction. This is because the resulting field has an alternative component with dissipative effects depending on its position. They will be more important if the component oscillates in the middle of magnets and less important in the middle of gap between them

Single Line-to-Ground Fault Detection in Face of Cable Proliferation in Compensated Systems

ISBN: 978-953-307-037-7livre "Fault Detection" edited by Wei Zhang, In Tech 201

Isopod trackways from the Crayssac Lagerstätte, upper Jurassic, France

International audienceWell-preserved arthropod trackways are described from the laminated limestones of the Crayssac Lagerstätte (south-west France, Lower Tithonian). They occur in sediments deposited in the temporary coastal mudflats of intertidal to supratidal zones. The trackways are referred to Pterichnus isopodicus isp. nov., and are interpreted as the locomotion traces of isopods. Different trackway morphotypes are recognized and clearly resulted from variations in the original consistency of the sediment. Sinuous trackways may correspond to vagrant activity on wet mud whereas numerous straight ones indicate a more rapid crawling on a soft-to-firm substratum (e.g. tidal flat during emersion). The preferred orientation of trackways indicates that isopods were crawling in a direction perpendicular to shoreline as a result of possible taxis induced by sediment wetness and ⁄ or by a migratory behaviour controlled by tidal rhythm. Unusually long emergence of the sediments may have favoured the preservation of dense networks of trackways. An isopod identity is supported by the general morphology of the tracks and the association of trackways with isopod body fossils. Archaeoniscus, which occurs abundantly in Late Jurassic deposit

Influence of Power Converter Losses Evaluation in the Sizing of a Hybrid Renewable Energy System

International audienceAn improvement to the precision of losses calculation in static converters used in a hybrid renewable energy system (HRES) is presented in this article. The objective is to be able to evaluate energy losses in the system during the unit sizing process. The models developed in this paper consider the conduction and switching losses to take into account the variation of the converters efficiency together with the load variations. The proposed approach for the energy losses calculation is tested with an already sized HRES. The methodology is compared on an hour-byhour basis with a constant efficiency rate approach using a specially developed simulation program. The importance of the correct energy losses evaluation is demonstrated

L’involontaire psychique du Projet Professionnel Personnalisé

L’instauration du PPP répond à un double souci d’orientation professionnelle et d’accompagnement personnalisé de l’étudiant. Pour peu qu’il soit mis en œuvre par un spécialiste de la psyché avec l’assentiment bienveillant de l’équipe enseignante, ce second volet ouvre sur une série de phénomènes psychiques et d’expériences transférentielles dignes d’intérêt pour la communauté pédagogique. Il révèle surtout cette dimension sous-jacente et inconsciente de l’encadrement, voire celle de la « prise en charge » et de ce « savoir insu », autant d’éléments recherchés par les étudiants qui s’inscrivent dans les IUT. Cet aspect apparaît amplement au point de devenir lui-même objet du séminaire et sujet de débats dans les différents exercices, dynamiques de groupe, travaux de présentations et exposés oraux accomplis au cours de l’année. On ne peut d’ailleurs que constater une « demande », le plus souvent explicite, des étudiants sur ce fragment d’eux-mêmes auquel ils semblent attacher une grande importance pour leur réussite sur le marché de l’emploi. En conséquence et à titre de témoignage, l’auteur se propose de communiquer les résultats de son travail en la matière dans les différents départements de l’IUT de Nice Sophia Antipolis où il enseigne depuis plusieurs années (Techniques de Commercialisation, Gestion des Administrations et des Entreprises, Carrières Sociales).The introduction of PPP serves the student in two ways : 1. with vocational guidance and 2. with personalized support. When the program is implemented by a specialist of psychology along with the support of the faculty, this second part opens a wide range of psychological phenomena and transferential experiences that would be of interest to the educational community as a whole. It especially reveals the underlying and unconscious dimension of this structure and the dynamic involved in it, even that of the desire for support including the “unknown knowledge” ; all of which is sought after by the students enrolled in IUT. Eventually this aspect in itself grows to the point of becoming the topic of the seminars and the subject of debates in various exercises, group dynamics, work and oral presentations made during the academic year. We will also see often explicit “application” of this fragment of themselves from the students to which they give great importance both on their way and in the job market. Resultantly and as testimony the author proposes to present the results of his work in the different departments (TC, GEA and CS) where he has been teaching for several years