Scientific direction Development of key enabling technologies
Transfer of knowledge to industry

PhD : selection by topics

Engineering science >> Electromagnetism - Electrical engineering
3 proposition(s).

Optimal Battery Management Algorithms for Switched Cell Architecture Systems

Département Systèmes

Laboratoire Electronique Energie et Puissance

01-10-2018

SL-DRT-18-0663

vincent.heiries@cea.fr

Although having benefited from major advances in recent years, batteries still suffer from certain limitations, notably in terms of energy density, lifetime and sometimes safety. In this context, the patented switch-cell battery architecture proposed and developed in the L2EP laboratory represents a major innovation in this field and allows us to go beyond some of these limitations. Today, batteries are essentially composed of a series of cells through which the same current is flowing. These systems are thus limited by the weakest cell in series. One of the advantages of the switched cell architecture is that each cell can be exploited in a differentiated way and thus get the most out of each cell. A first objective of the thesis is precisely to propose an algorithm allowing to exploit at best the energy of all the cells of the battery in order to increase the autonomy of the system while maximizing its lifetime. A second objective of this thesis is the development of innovative estimation algorithms for SoX indicators (SoC: State of Charge; SoH: State of Health, SoE: State of Energy) of accumulators based on an optimal use of the new capabilities offered by the switched cell architecture. Indeed, this architecture brings new functionalities that open the door to the implementation of new algorithms within the Battery Management System. In particular, cell capacity estimation could be greatly improved by on-line correction of the estimator. This procedure can be made possible by a controlled load-discharge profile of individual cells.

Wireless and powerless sensor antenna with frequency transposition

Département Systèmes

Laboratoire Antennes, Propagation, Couplage Inductif

01-09-2018

SL-DRT-18-0742

camille.jouvaud@cea.fr

The thesis takes place in the context of the development of the Internet of Things and its reliability to connect and automatically transfer data over a large network. In this context, needs for real time information are intensified. Therefore, new wireless sensor that consumed as less as possible are expected. Among existing sensors technologies, electromagnetic sensors have a strong interested in their passive side Those sensors, which are read remotely by an interrogating antenna, use the variations of electromagnetic properties of an antenna to measure a physical phenomenon. Development and optimisation of those sensors properties, of their communication abilities as well as their miniaturization constitute a major stake for their generalization in our professional or private environments. Moreover, constraints imposed by the different medium where the sensors will be implemented, and so where the data will be transferred, imply some issues in terms of detectability and reliability. This thesis proposes to contribute to the problem of the miniaturization of the sensor-antennas and their sensitivity towards the propagation channel, through the study of the properties of miniature antennas themselves as well as the methods of interrogation of these antennas.

Non Destructive Testing by Eddy Current method of metal parts obtained by Additive Manufacturing

Département Imagerie Simulation pour le Contrôle (LIST)

Laboratoire Instrumentation et Capteurs

01-09-2018

SL-DRT-18-0833

natalia.sergeeva-chollet@cea.fr

CEA/LIST develops methods of Non Destructive Testing (NDT) by Eddy Current (EC) methods for various industrial sectors such as aeronautics, oil and gas industry, or nuclear industry. In these industrial fields, metal additive manufacturing is booming but is often limited by the lack of a control solution of the produced parts ensuring the integrity of the parts. To make progress in this sector, an "Additive Factory Hub", located at CEA in Saclay, was created and inaugurated at the end of last year. The current methods of monitoring and control of the produced parts are based on an optical examination of the surface of the part being manufactured by a camera or to monitor the atmosphere of the manufacturing chamber. The purpose of the proposed subject is to implement a surface and sub-surface inspection by Eddy Currents of the additive manufacturing parts. The PhD student will contribute to the improvement of the control of the pieces. He or she will invest in the optimization of Eddy Current sensors and associated working frequencies, in order to increase the sensitivity to the defects to be detected, such as superficial or sub-surface melting defects and local porosities. These optimizations will be conducted by simulation based on the CIVA simulation platform developed in the department (http://www-civa.cea.fr). He or she will proceed to the experimental evaluation of these sensors. Signal processing algorithms will also be developed to minimize the impact of the roughness of the parts. To carry out these works, knowledge in electromagnetism, instrumentation and electronics is desired.

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