Characterization and modeling of partial discharges (PD) in power converters based on WBG components

The field of power electronics is currently undergoing a major revolution thanks to the emergence of wide bandgap (WBG) components, such as SiC and GaN. These technologies pave the way for power converters capable of operating at unprecedented voltages, frequencies, and temperatures, while significantly increasing power density.
However, this enhanced performance introduces new challenges for the dielectric materials used in power modules. Ultra-fast switching and extremely steep voltage edges (up to several tens of kV/µs) impose unprecedented stresses on electrical insulation. Among the critical phenomena to control, partial discharges (PDs) play a central role: they can originate from design defects, lead to premature aging of insulating materials, and affect module reliability.
The direct relationship between PD activity and reliability makes their understanding and measurement essential. While current methods allow the characterization of PDs under 50 Hz AC voltage, no standardized framework exists for steep voltage edges, representing a significant scientific challenge.
Thesis Objective:
This thesis aims to address this challenge by combining experimental and modeling approaches to characterize partial discharges in WBG power modules intended for high-voltage, high-frequency applications. The goal is to gain a better understanding of aging mechanisms and optimize converter design to ensure reliability, lifetime, and electrical performance.

Keywords: Power electronics, SiC/GaN, modeling, partial discharge (PD), electrical insulation

• Academic supervisor    HdR Eric VAGNON, Laboratoire AMPERE UMR CNRS 5005  https://orcid.org/0000-0002-9603-519X
• Doctoral School    ED 160 EEA, Ecole Centrale Lyon
• IFPEN supervisor    PhD, Laid KEFSI, https://orcid.org/0009-0006-6926-652X
• PhD location    IFPEN, Rueil-Malmaison, France  
• Duration and start date    3 years, starting in the fourth quarter 2026
• Employer    IFPEN
• Academic requirements    Master’s Degree or Engineering Degree in Electrical Engineering
• Language requirements    English level B2 (CEFR)
• Other requirements    Signal Processing

To apply, please send your cover letter and CV to the IFPEN supervisor indicated here below.