The main objective of this thesis is to develop a methodology to size PETT topologies, in order to compare them.
PhD Quentin MOLIN « High Voltage SiC MOSFET Robustness study: threshold voltage shift and short-circuit behaviour »
This manuscript is a contribution to reliability and robustness study of MOSFET components on silicon carbide “SiC”, wide band gap semiconductor with better characteristics compared to silicon “Si” material. Those new power switches can provide better switching frequencies or voltage withstanding for example in power converter. SiC MOSFET are the results of approximately 10 years of research and development and can provide increased performances and weight to some converter topology for high voltage direct current networks.
Gate-oxide technology weakness is a main reliability issue of Silicon Carbide MOSFET transistors. The threshold voltage shift is a critical phenomenon that addresses the reliability of industrial power applications. It is important to have a better understanding of the phenomena implied in the gate threshold voltage shift. In this context, HTGB test is proposed and the resulting gate oxide stress is studied and discussed in this paper.
Robustness study for the 1.7 kV SiC MOSFET is presented. After evaluation of the critical energy required for failure, devices were submitted to repetitive short-circuits conditions.
This article presents the design, the fabrication, and the test of an isolated DC-DC converter for renewable energy applications. The converter is based on the Dual Active Bridge topology and uses silicon carbide power semiconductors and a medium frequency transformer. The design process covers hardware ranging from the semiconductor die to the complete power converter. For the control, a rapid prototyping approach was used. The experimental validation of the 100 kW prototype is presented.
This paper presents a methodology to optimize the sizing of such power converters in order to compare different topologies for a given application. The proposed procedure maximises the efficiency of the converter under a limited volume.
Our High Current Switching test bench is now operational! This one is integrated to the Power switches characterization platform, which can be used to fully characterize power switches.
Semi-Analytical Methods for Calculation of Leakage Inductance and Frequency-Dependent Resistance of Windings in Transformers
This paper focuses on analytical or semi-analytical calculation techniques to be integrated into a medium frequency transformer optimization process.
Theoretical and experimental analysis of the soft switching process for SiC MOSFETs based Dual Active Bridge converters
In the new electrical grids, series/parallel converters architectures can be considered for medium and high voltage power conversion. Dual Active Bridge (DAB) topology is a serious candidate to be implemented within these converters.
This paper presents an overview of the DC-DC power converters dedicated to HVDC proposing a classification based on their structure.