Thesis (PhD) - Validation methodology of advanced CHM functions and Digital Twin for Railway traction converters based on multi stress accelerated tests W/M

General context

The Power Electronics and Converters programme focuses on MVDC and HVDC (medium- or high-voltage direct current) power converters. Our aim is to provide innovative solutions for converters with improved performance and additional functionalities for scalable DC systems, integrating large quantities of renewable energy and enabling safe, resilient and economical hybrid (AC-DC) systems.

Subject of the thesis

The R&D team at SuperGrid Institute (Villeurbanne), in collaboration with Alstom and with support from Politecnico di Torino (Italy), is offering an exciting PhD opportunity focused on the validation of advanced Condition and Health Monitoring (CHM) functions and the development of Digital Twins for railway traction converters.
This research work is part of the POWERDIAG project, funded by the French National Research Agency (ANR).

The development of advanced conditions and health monitoring functions for power electronics converters used in railway traction relies on validated and robust lifetime models for each degradation mechanism, robust algorithms for the prediction of Remaining Useful Life (RUL) and trained Digital Twins.

The validation of these approaches is challenging because they must be implemented in the early design phase while their benefits are expected in the long term (a railway converter is designed for 30 years typically) with no possibility to run test without acceleration factors.

As a consequence, dedicated methodologies and test benches must be developed in order to generate the necessary datasets to support the validation activities.

Supergrid Institute has developed a multi-stress test bench combining accelerated load cycling stress with hard switching under high voltage, high current conditions to be as close as possible to the real application conditions. Phenomena at different time scale are reproduced on this test bench (from semi-conductor switching ( #10 µs) to reproduction of a railway use profile in the minute range). This test bench is extensively instrumented (Vce, Vce sat, I load, I switch, Vge, Tcase, Tjunction, …). A new test bench with higher current and voltage capabilities will be designed during the project to perform Power Cycling Test (PCT) and also Short-circuit stress, for Si IGBT but also SiC MOSFET.

Objectives / Missions

In this context, the PhD candidate will be responsible for developing a methodology to support the experimental activities carried out on the multi-stress test bench, with the objective of maximizing the insights gained from the tests and optimally processing the generated data.

Several research questions have been identified:

• How can a relevant multi-stress test plan be developed, taking into account meaningful combinations of stress factors and their respective levels?

• How can this test plan be optimized for the targeted technology, while meeting industrial requirements to reduce the number, duration, and cost of tests?

• How can the experimental data be processed while accounting for the variability of different factors (statistical approach)?

• How can the most relevant datasets be selected, measured, and extracted for training the Digital Twin, striking a balance between data volume and model accuracy?

Degree in Electrical Engineering, specialising in Power Electronics. Knowledge of semiconductor physics would be appreciated.

• Electrical engineering and power electronics, in particular :

  • Signal processing, metrology, sensors and instrumentation

  • Physics of ageing mechanisms

• An aptitude for experimental work

  • Operation of test benches

  • Development of measurement methods (digital and analogue electronics)

• Fluency in French and English.

• Knowledge in system modeling, component reliability, and statistical processing of experimental data

Soft Skills

• Strong analytical and summarising skills;

• Teamwork;

• Autonomy;

• Thoroughness;

• Organisational skills;

• Curiosity and creativity;

PhD Supervisor: Francesco IANNUZZO
Enrollment Institution: Politecnico di Torino
Industrial Supervision: SuperGrid Institute, in collaboration with Alstom
PhD Candidate Location: Mainly at SuperGrid Institute, Villeurbanne (France), with possible mobility to Politecnico di Torino (Italy)
Duration and Start Date: 3 years, starting from Fall 2025 (possibility to start earlier under a fixed-term contract)

Join a dynamic team within a leading applied research institute, working closely with the railway industry!

Other information

When you join SuperGrid Institute, you'll be part of a dynamic working environment.

At SuperGrid Institute, we respect and value the diversity of our employees, their backgrounds and experiences, with the aim of providing equal opportunities for all.

Diversity is at the heart of our operations and we are committed to banning all discrimination from our human resources management. SuperGrid Institute makes all its positions accessible to people with disabilities and is committed, as part of its action plan for professional equality, to paying particular attention to applications from women in order to achieve a balanced overall distribution of the workforce.