Study and design of a test bench for electrothermal characterisation and ageing of power devices
Direction Mobilité et Systèmes

IFP Energies nouvelles (IFPEN) est un acteur majeur de la recherche et de la formation dans les domaines de l’énergie, du transport et de l’environnement. De la recherche à l’industrie, l’innovation technologique est au cœur de son action, articulée autour de quatre priorités stratégiques : CLIMAT, ENVIRONNEMENT ET ÉCONOMIE CIRCULAIRE, ÉNERGIES RENOUVELABLES, MOBILITÉ DURABLE et HYDROCARBURES RESPONSABLES.

L’engagement d’IFPEN en faveur d’un mix énergétique durable se traduit par des actions visant :

• à gagner en efficacité énergétique ;
• à réduire les émissions de CO2 et de polluants ;
• à améliorer l’empreinte environnementale de l’industrie et des transports ;

tout en répondant à la demande mondiale en mobilité, en énergie et en produits pour la chimie.

Dans cet objectif, IFPEN développe des solutions permettant, d’une part, d’utiliser des sources d’énergie alternatives et, d’autre part, d’améliorer les technologies existantes liées à l’exploitation des énergies fossiles.

Study and design of a test bench for electrothermal characterisation and ageing of power devices

Power electronic systems play a central role in modern applications such as electric mobility, renewable energy and industrial systems. They convert and control electrical energy while meeting demanding requirements for efficiency, compactness and reliability. However, their operation inevitably generates power losses, mainly through semiconductor conduction and switching. These losses increase the junction temperature, a key factor affecting device performance and lifetime. More accurate loss modelling is therefore needed to understand the thermal behaviour of these devices and anticipate the associated ageing mechanisms.

This internship will focus on developing a back-to-back test bench for power device characterisation. The objective is to improve the accuracy, reliability and repeatability of conduction and switching loss measurements under electrical and thermal stresses representative of actual operating conditions. The bench will also incorporate measurements of temperature-sensitive electrical parameters (TSEPs) to enable accurate junction temperature estimation. Losses will be assessed using on-state electrical quantities, such as Vds_on and Rds_on, and by analysing switching energies (Eon, Eoff, etc.) during switching transitions.

The first step will be a critical review of the existing test bench architecture, including its topology, instrumentation and control strategy, to identify technical limitations affecting measurement quality and stress control, and propose improvements. The bench will incorporate power cycling capabilities to impose controlled thermal cycles with specified junction temperature swings (ΔTj), frequencies and durations, reproducing stresses representative of actual device operation. Ageing-sensitive electrical parameters, such as threshold voltage (Vth), on-state resistance (Rds_on) and switching times, will be monitored throughout the tests to characterise degradation mechanisms.

The work will follow an integrated electrothermal approach, correlating power losses with thermal stresses and changes in device state of health. The aim is to provide reliable experimental data for modelling, improve methods for assessing the reliability and lifetime of power transistors, and develop recommendations for the design and sizing of more robust and durable power electronic systems.

Candidate profile:

Engineering student or final-year Master’s student with a solid background in electrical engineering, power electronics and thermal modelling.

Desired technical skills:

• Knowledge of power electronics and semiconductor devices (SiC, GaN).
• Simulation tools (MATLAB/Simulink, LTspice, PLECS).
• Experience in electronic design and thermal modelling would be an advantage.

Personal qualities:

• Curiosity and a desire to innovate.
• A proactive attitude and the ability to work in a team. The intern will interact with PhD students and engineers working in the field.
• Motivation for experimental validation and dissemination of results through scientific publications.

Keywords: Power electronics, back-to-back test bench, junction temperature, thermal engineering, modelling, reliability.

Duration and location: Six months, from March to August 2027, in Rueil-Malmaison, France.