Improving the operation of power grid and offering new smart applications, the deployment of a supervisory infrastructure is necessary. One solution to transmit data may be based on the power-line ...communication (PLC) technology. It consists of the superposition of high-frequency signals with the electrical signal of 50/60 Hz. However, the power grids have not been designed to operate in high frequencies. Therefore, they provide a transmission channel with difficult propagation conditions. This paper deals with the modeling of the medium-voltage/low-voltage (MV/LV) power transformers in PLC frequencies. The proposed models are based on the "lumped model" and "black box model." They are performed in the frequency band from 1 kHz to 1 MHz on SPICE and MATLAB software, respectively. These models are based on impedance measurements and validated by experimental data. The advantages and drawbacks of each model are detailed from the presentation of the modeling method and simulation results. The comparison of the simulation results show that "black box model" offers good accuracy. The transmission results show that transformers are an important element in PLC studies because they provide significant losses. Moreover, these losses depend mainly on the values of the impedance terminals of the MV/LV transformer.
Wearable sensor makes possible today to obtain motion measurement for health monitoring, physical activity assessment, or sport performance evaluation in ecological environment. One of them, the ...inertial measurement unit (IMU), is extensively used to obtain measurements relative to human motion. The IMU, composed of 3D gyroscope, accelerometer, and generally magnetometer, can be used to provide an orientation in a global coordinate system after fusion of the different sensor data.
A sensitivity study for an indoor channel VAUZELLE, Rodolphe; POUSSET, Yannis; ESCARIEU, Frédéric
Annales des télécommunications,
05/2004, Letnik:
59, Številka:
5-6
Journal Article
Cet article présente un outil d'aide à la compréhension des mécanismes de propagation des ondes électromagnétiques dans un environnement donné. Plus précisément, il s'agit d'un logiciel interactif ...qui constitue un support de cours permettant, grâce à de nombreuses animations, de visualiser : l'évolution spatio-temporelle d'une onde en s'appuyant sur la propagation de son front d'onde ; la déformation de ce front lors d'interactions avec des objets (réflexion sur des faces et diffractions sur des arêtes) ; le phénomène d'interférences. Ce logiciel permet notamment d'illustrer des problèmes liés à l'interface radio pour les systèmes mobiles. Dans ce contexte, au département EEA de la Faculté des Sciences de Poitiers, nous l'utilisons en complément d'un simulateur de canal de propagation par trajets multiples.
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