Conception d’un module d’électronique de puissance “Fail-to-short” pour application haute tension- Ilyas Dchar -THESE de DOCTORAT DE L’UNIVERSITE DE LYON

Conception d’un module d’électronique de puissance “Fail-to-short” pour application haute tension- Ilyas Dchar-  THESE de DOCTORAT DE L’UNIVERSITE DE LYON Designing a Power Module with Failure to Short Circuit Mode Capability for High Voltage Applications 

Abstract
The reliability and endurance of high power converters are paramount for future HVDC networks. Generally, module’s failure behavior can be classified as open-circuit failure and short-circuit failure. A module which fails to an open circuit is considered as fatal for applications requiring series connection. Especially, in some HVDC application, modules must be designed such that when a failure occurs, the failed module still able to carry the load current by the formation of a stable short circuit. Such operation is referred to as short circuit failure mode operation. Currently, all commercially available power modules which offer a short circuit failure mode use silicon semiconductors. The benefits of SiC semiconductors prompts today the manufacturers and researchers to carry out investigations to develop power modules with Fail-to-short-circuit capability based on SiC dies. This represents a real challenge to replace silicon power module for high voltage applications in the future. The work presented in this thesis aims to design a SiC power module with failure to short circuit failure mode capability. The first challenge of the research work is to define the energy leading to the failure of the SiC dies in order to define the activation range of the Fail-to-short mechanism. Then, we demonstrate the need of replacing the conventional interconnections (wire bonds) by massive contacts. Finally, an implementation is presented through a "half bridge" module with two MOSFETs.

Keywords : Press-Pack, Sandwich structure, conventional module, HVDC converter, Packaging, Failure, Short-circuit, Avalanche, Critical energy, Explosion, Stability, SiC.

LINK:
https://tel.archives-ouvertes.fr/tel-01784733/file/these.pdf