Compteur électrique | EPFL Graph Search

alt=|vignette|Compteur électrique modulaire couramment utilisé pour toutes les applications de sous-comptage comme le suivi de la consommation de bornes de recharge, de stations photovoltaïques Un compteur d’énergie électrique ou compteur d’électricité ou compteur électrique est un organe électrique servant à mesurer la quantité d'énergie électrique consommée dans un lieu : habitation, industrie… Il est utilisé par les fournisseurs d'électricité afin de facturer la consommation d'énergie au client. À l'origine ces appareils étaient de conception électromécanique, ils sont remplacés dorénavant par des modèles électroniques. Les nouvelles versions de compteurs électriques sont des compteurs communicants appelés parfois « compteurs intelligents ». L'unité légale d'énergie est le joule (J). Le watt (W), unité de puissance, correspondant à un flux d'énergie d'un joule transféré en une seconde. Cependant, l'unité d'énergie habituellement utilisée pour la consommation électrique est le kilow

Aspects of the energy transition and their effects on power systems

Laurent Vincent Pagnier

Most European countries are committed to an energy transition which consists in the substitution of conventional CO2 emitting energy sources by new renewable energy sources (RES), in particular wind and solar power. As opposed to conventional energy sources, new RES are distributed, non-dispatchable, fluctuating and inertialess and have negligible marginal costs. In this thesis, we investigate the impact of the energy transition on the electricity sector in Europe. In the first part of this thesis, we investigate the future electricity production and prices in Europe. We develop a dispatch algorithm on an aggregated model of the pan-European power grid with which we study the future European productions. We show that, as the penetration of new RES increases, the transmission grids are more strongly used and that more flexibility is required from conventional generators. The existing infrastructures seem to able to absorb, through increased international power exchanges and usage of the existing pumped-storage hydroelectricity, the variations of new RES productions even for high penetrations. Then we investigate the effects of new RES on electricity prices. We explain why, due to their negligible marginal cost and their lack of dispatchability, they tend to drag electricity prices down and can be considered as a reduction of the load in the electricity pricing. In particular, photovoltaics decreases the volatility of electricity prices. We show that, in most European countries, the day-ahead electricity price is strongly correlated with the residual load, which is obtained by subtracting the non-dispatchable productions, in particular those of the new RES, from the load. From this observation, we build an effective price model based solely on the residual load with which the revenues of different electricity producers are evaluated. The second part of this thesis deals with disturbances in large transmission grids. The substitution of conventional generators by inertialess RES reduces the amount of inertia connected to power systems which might affect their reliability. To examine the propagation of disturbances in large transmission grids, we develop a dynamical model of the continental European transmission grid. We observe that the magnitude of the disturbance following a power loss depends on the fault location. We show that when inertia and primary control are uniformly distributed, the faults exciting the slowest eigenmodes of the network Laplacian are followed by the strongest disturbances. Reducing inertia on those eigenmodes, which are mostly located in the periphery of the grid, affects more its resilience than when the reduction occurs in its center. Finally, we use perturbation theory to derive algorithms for optimal placement of inertia and primary control when some mild inhomogeneities are present in their distributions. We show that,when the vulnerability of the whole grid is taken into account, a uniform distribution of inertia is optimal and the primary control is best placed in the periphery of the grid.

EPFL2019

SOI mixed-mode design techniques and case studies

Marija Blagojevic

Since the emergence of Silicon On Insulator (SOI) technology the research activities have been concentrated on a detailed analysis of SOI devices and their use in different application fields (low-voltage, low-power circuits, high temperature electronics, digital circuits, etc.). The present thesis deals with low-voltage, low-power mixed-mode design using a SOI technology. The goal is to establish the concepts that allow one to design SOI mixed-mode circuits, and to apply these concepts to the design of fully depleted (FD) and partially depleted (PD) SOI circuits and systems. Two studies have been realized in the scope of this work: a Hall sensor based microsystem design using an experimental FD SOI technology a DRAM design using capacitor-less 1T floating-body PD SOI memory cells. At the beginning of this thesis, two major types of SOI devices are introduced, namely FD and PD devices. The most important properties of these devices are then presented and compared to those of CMOS bulk devices. A design methodology based on design retargeting from bulk to SOI technology is further proposed. This methodology is developed with the aim of being implemented for the design of FD SOI circuits. It consists in using the same device dimensions and bias currents for the bulk and the corresponding FD SOI design. The analysis performed proves that such an approach permits one to obtain better circuit performances using the FD SOI technology. The EKV model is chosen for Spice simulations. For that purpose the extraction of the EKV intrinsic parameters has been performed for the experimental 0.5 μm FD SOI technology. The EKV model card obtained from transistor measurements is implemented straightforwardly for circuit simulations. The first study presented in this thesis is an FD SOI Hall sensor front-end for energy measurement. The mixed-mode microsystem design is completely based on the proposed design methodology. The system level solutions are also included, such as the spinning-current method that serves for reduction of the offset and low frequency noise of the analog front-end, and a high resolution analog-to-digital conversion technique. The integrated microsystem is entirely functional. Furthermore, according to the existing literature, this integrated circuit is the first microsystem completely realized using FD SOI technology. The overall system error that is obtained is less than 1.5 %. During the second part of this work, a novel sensing scheme that exploits an automatic reference generation based on successive approximations has been developed for the PD SOI capacitor-less 1T DRAM. The 1T DRAM reference current is generated by an adjustable current source. The electrical calibration of the reference current is performed using a digital-to-analog converter and successive approximations algorithm. The proposed scheme is evaluated in a 2 kb test chip. The circuit integrated using PD SOI technology contains a 2 kb 1T memory array, as well as automatic reference generators and peripheral circuits. The automatic reference generator comprises current mode sense amplifier, M/3M converter, and successive approximations register. All blocks implemented in the test chip are described in detail, and PD SOI design issues are discussed. A number of experimental results demonstrate the potential of the PD SOI 1T DRAM for future embedded DRAM applications. The measured retention time under holding conditions is higher than 1s. In the continuous read mode, a few hundreds of the read cycles can be performed without a refresh operation. The test chip has a measured access time of 25 ns with a read cycle time of 70 ns.

EPFL2005

Evaluating the electricity saving potential of electrochromic glazing for cooling and lighting at the scale of the Swiss non-residential national building stock using a Monte Carlo model

Olivia Valérie Charlotte Bouvard, Jean-Louis Scartezzini, Andreas Schueler

Novel electrochromic glazing technology has been identified as an emerging option for reducing cooling and lighting electricity demand. As this technology is particularly promising for office building we assess the related technical energy saving potential in case of nation-wide implementation in Swiss office buildings. A Monte Carlo model of Swiss office building stock using distributions of empirical building characteristics was coupled with a statistical model of energy savings of electrochromic glazing. The building stock model for Swiss office buildings was shown to produce cooling and lighting electricity demand estimates in agreement with the existing case study literature. Total yearly electricity demand for lighting and cooling was calculated to be 1152 ± 32 GWh. Electrochromic glazed saved 125 ± 6 GWh or on average 11% of lighting and cooling electricity demand. Electrochromic glazing was found to be particularly effective in highly cooled office buildings, where cooling accounted for 20 kWh/m2 and total electricity saving potential was estimated at 5.5 kWh/m2 or 5.2% of today’s typical total electricity demand of an office building across all uses. Areas where electrochromic glazing would have particularly high potential are highlighted.