Optimisation Géométrique d'une Machine à Commutation de Flux à Aimants Permanents en utilisant un Modèle Analytique Magnéto-Acoustique

Cet article présente les résultats d'une optimisation de la géométrie des Machines à Commutation de Flux à Aimants Permanents (MCF-AP) basée sur des critères multi-physiques magnéto-acoustiques en utilisant un modèle entièrement analytique visant à prédire le fonctionnement magnétique, mécanique et acoustique de ces structures. L'optimisation est réalisée sur une structure triphasée 12/10 et sur une structure pentaphasée 20/18 pour une alimentation et une vitesse donnés. Le modèle analytique, présenté et validé expérimentalement, permet un gain de temps non négligeable dans la prédiction des phénomènes magnéto-acoustiques en comparaison d'un modèle éléments finis et permet naturellement son implémentation dans un algorithme d'optimisation

Embedded Simple Excited Automotive Alternator Modeling using Magnetic Equivalent Circuits

This paper presents the modeling by Magnetic Equivalent Circuit model (MEC) of a Simple Excited Automotive Alternator (SE2A) where DC-excitation winding is transferred from rotor side to statorone rather than in conventional automotive claw pole alternators, to overcome the disadvantages of the ring-brush system. Following the resolution of the MEC using Newthon-Raphson numerical method, the alternator performances at both no-load and under resistive load regimes is achieved considering the saturation effect. It has been found that alternator’s performances carried out using the proposed MEC are with closed proximity to experimental records on a built prototype of the considered alternator

Experimental investigation of a Doubly-Excited Flux-Switching Machine for Aircraft DC Power Generation

International audienceThis paper presents an experimental study on a new design of a Doubly-Excited Flux-Switching Machine (DEFSM) proposed for variable speed DC power generation in future aircraft. This machine uses excitation coils associated with permanent magnets to control the flux-linkage. This gives the possibility of using a diode bridge rectifier which is more reliable than an active bridge. After presenting its design and some of its main characteristics, an experimental investigation of the electromagnetic and thermal performances has been performed on a 3 kW prototype. It is shown that the generated power can be easily controlled using the excitation current which is very interesting for wide-speed-range applications. The unique design of the stator makes it possible to have a low remanent back EMF. This characteristic makes this machine inherently safe in case of fault since no flux weakening is needed. The thermal analysis has shown that the permanent magnets can be kept at relatively low temperatures which makes them more resistant to demagnetization. All of this makes the DEFSM a strong candidate for future aircraft power generation

Quality and Trace Element Profile of Tunisian Olive Oils Obtained from Plants Irrigated with Treated Wastewater

In the present work the use of treated wastewater (TWW) to irrigate olive plants was monitored. This type of water is characterized by high salinity and retains a substantial amount of trace elements, organic and metallic compounds that can be transferred into the soil and into the plants and fruits. In order to evaluate the impact of TWW on the overall quality of the oils, the time of contact of the olives with the soil has been taken into account. Multi-element data were obtained using ICP-MS. Nineteen elements (Li, B, Na, Mg, Al, K, Ca, Sc, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, Mo, Ba and La) were submitted for statistical analysis. Using analysis of variance, linear discriminant analysis and principal component analysis it was possible to differentiate between oils produced from different batches of olives whose plants received different types of water. Also, the results showed that there was correlation between the elemental and mineral composition of the water used to irrigate the olive plots and the elemental and mineral composition of the oils

African Linguistics in Central and Eastern Europe, and in the Nordic Countries

Non peer reviewe

Language endangerment and language documentation in Africa

Non peer reviewe