18 Novembre – Thesis defense - Guillaume Mejecaze
10 h30 Amphi Jean-Paul Dom - laboratory IMS / building A31 (Talence campus)
Destructions analysis of power supplies due to high level current pulse.
For thirty years, the threat of electromagnetic pulses caused by a high-altitude nuclear explosion (NEMP / HEMP) is still an actual concern in the field of security and safety. NEMP couples efficiently on aerial lines of the electricity network allowing to supply houses and factories. Once coupled to these lines, the generated interference can then be propagated to the first encountered systems and disturb or destroy them. In most cases, these systems are household or industries appliances power supplies. In this context, destruction effects of electronic power supplies due to high level current pulse injection
are studied thanks to an injection generator called PIC for Current Injection Platform. A flyback switch mode power supply (SMPS), representative of a majority of common power supplies, has been designed for the thesis in order to fully control its topology and components. The most susceptible components in SMPS have been identified and have been destroyed due to a too high level current over an excessive duration compared to their maximum ratings. These understandings have been supported by X-rays and optical microscope analyzes. These ones allowed to provide first hypotheses on their destruction cause, which were then confirmed by current and voltage measurements on each component during the pulse injection. Finally, PIC and the designed SMPS have been modeled using a Spice electronic simulation software. This thesis is the first step of a work whose final objective is to model the susceptibility of SMPS in order to predict their destruction level.