Characterization and modeling of Partial Discharges (PD) in the windings of electrical machines for automotive traction

The massive introduction of electric vehicles presently is a key contributor to make automotive transport more durable. This in particular requires the ability to design more efficient and low-cost electric powertrains in order to increase the vehicles’ autonomy and to make them more competitive on the market. 
In this context, a key challenge is the usage of electric components with high power and torque density. This induces increased levels of DC bus voltage, as well to the need for employing new wide-band gap semiconductor materials (SiC and GaN). As a result, steeper voltage fronts are encountered in the windings, that can favour of a rapid electrical ageing if the threshold of appearance of partial discharges (PD) is reached. 
The objective of the PhD thesis is to develop a methodology for characterizing and modeling partial discharges, while considering the impact of the feeding inverter and of environmental parameters. During a first experimental part, the PhD student will be in charge of developing an experimental methodology to characterize the voltage distribution in a winding subjected to steep voltage fronts under conditions representative of realistic operating and environmental parameters, and to further develop it to study and characterize the Partial Discharges Inception Voltage (PDIV). During an ensuing modeling phase, the PhD student will develop a predictive model for the voltage distribution in the windings as a function of temperature and frequency variations, as well as a predictive model of the Partial Discharges Inception Voltage (PDIV).

Keywords: Electric system, electric machines, windings, insulation, inter-turn voltage, overvoltage, partial discharges, reliability, wide gap converter.

• Academic supervisor    Professor Stéphane DUCHESNE, LSEE, Artois University, stephane.duchesne@univ-artois.fr
• Doctoral School    Doctoral School « Sciences pour l'ingénieur de Lille (ED072) », http://edspi.univ-lille1.fr
• IFPEN supervisor    Doctor Abdenour ABDELLI, Research engineer, abdenour.abdelli@ifpen.fr  
• PhD location    IFPEN, Rueil-Malmaison, France 
• Duration and start date    3 years, starting in the  fourth quarter of 2022
• Employer    IFPEN, Rueil-Malmaison, France.
• Academic requirements    MSc in electrical engineering
• Language requirements    Fluency in French and English