Conception d'un convertisseur DC/DC à très haute fréquence pour l'alimentation d'une cellule radar, contributions à son intégration

This thesis report deals with the issue of integration of isolated DC-DC converters operating at low power high frequency and high efficiency. To begin with, the particular environment of this converter is presented. This is the field radar avionics power supply, for which electrical, mechanical, EMC specifications are hard. Therefore, this part is a starting point for the converter specifications. The bellowing study details the choice of conversion structure that seems best for both, the environment but also specifications. On the other hand, this paper discusses the feasibility of co-sintering process for the realization of magnetic components. This components.which are essential to realized such of converter. It follows the selection and implementation of a ferromagnetic ceramic material specific to our application. This step led to the characterization of a model of evolution for magnetic losses tacking into account the magnetic induction amplitude and the operating frequency. The next step is the implementation of a tools of constrained optimization sizing for magnetic components such as transformers and resonance inductors. These elements are composed of our ferromagnetic ceramic suitable for 3MHz as witching frequency. However, one of the most critical points of this study proves to driver of the power switches. The driver requires a development of an original structure without which efficiency for 3MHz converter couldn't exceed 40% to 50%. Several patents results of this structure, as the particular converter regulation mode. In conclusion, this report presents the realized prototype and the very encouraging results that we have been obtained. A critical eye is focused on this functional achieving to open on the prospects for highly integrated co-sintered converter based on this thesis.