The first Thematic School on Dielectrics was organized under the sponsorship of CNRS—French National Research Center, and supported by DEIS, on Porquerolles Island in France, June 24 to 29, 2018. The topic of this first edition was the ageing and reliability of dielectric materials and related structures.

Group picture of the attendees of the Thematic School on Dielectrics 2018, Porquerolles Island, France.

Scope of the School

The ageing, breakdown, and life estimation of insulators are ancient problems though of utmost importance in many domains of electrical engineering and electronics. The evolution of power electronics technologies and new high voltage direct currents (HVDC) application introduce new threats for insulation (e.g., high frequency stresses, direct current issues, challenges of thermal endurance, etc.). At the same time, material compounding and processing is becoming more and more flexible, and new design possibilities are offered through material functionalization, use of nanocomposites, etc.

This first edition of the Thematic School on Dielectrics 2018 proposed to form a bridge between the old theories and the new technological opportunities, for researchers, engineers, and PhD students in the field of electrical engineering and, most importantly also, open our field and challenges to materials scientists, chemists, and physicists. The school was in the spirit of the Electrical Ageing Workshop, Autrans, France, organized in 2005 and 2008 with IOP support.

A total of 19 hours of plenary lectures were given on the following topics, involving lecturers from both the electrical engineering domain and from materials science:

• Issues and challenges related to insulation materials,
• Theoretical basis on dielectric properties of materials,
• Characterization techniques for insulations,
• Classical models of ageing and failure modes of dielectrics,
• Physico-chemical phenomena in ageing of insulators,
• Formulation and elaboration processes of ceramics,
• Process and properties of dielectric nanocomposites, and
• Bio-sourced insulating polymers.

The lectures addressed, on the part dedicated to the physics and withstanding of insulations, practical aspects of environmental stresses, new demands for materials, and various examples of failure mode. On the materials side, new opportunities for designing materials, with flexibility in properties, and opportunities for greener materials were presented. Beyond the courses, the opportunity for participants from different horizons to interact was certainly an invaluable aspect of the school.

Aside from these main courses, which were organized mainly as morning sessions, two activities took place. First, a round table with questions raised by younger researchers was organized in the last session of the school. The most original and demanding aspect of the school in terms of organization and logistics was the training of all participants on various measurement techniques on laboratory test benches. This latter unique activity was greatly appreciated by the participants.

The organizers of the Thematic School on Dielectrics. From left to right: Gilbert Teyssèdre, Petru Notingher, and Sombel Diaham.

Organization

The Thematic School on Dielectrics was supported by the French National Centre of Scientific Research (CNRS) and the IEEE Dielectrics and Electrical Insulation Society (DEIS). Moreover, the organizers were supported by the French Working Group on Dielectric Materials belonging to the SEEDS-CNRS Electrical Engineering Research Network.

The Thematic School on Dielectrics was held at the IGESA Center of Porquerolles Island, belonging to the French army as a recreation and meeting site. Porquerolles Island, on the French Riviera, is a protected area classified as the “Heart of National Park” since 2012. Due to accommodation restriction, the island is nearly free from tourists in the evenings, making it a quiet and natural place.

Continuing the discussions during lunchtime and coffee breaks in front of a beautiful sea view.

The dates were chosen to allow the overseas participants to attend the IEEE International Conference on Dielectrics (ICD), which was organized in Budapest during the following week.

Participants

For this Thematic School, 64 attendees registered and participated. Among them, 34 were from academia, 13 were from industry, and 17 were students. They came from many countries: UK, Italy, Sweden, Switzerland, the Netherlands, Czech Republic, Algeria, South Korea, and France. In total, 80 persons joined the event, making it a very successful event with respect to the ambition of the organizers; the full accommodation capacity was used.

Lectures, Practicals, and Instructors

As our objective was to bring international attendees to the event, the involvement of the DEIS, broadly advertising the event, and organizing it close to the ICD contributed to the school’s success. We also invited international and national experts and involved them within the training program.

John Fothergill (London City University), Stanislaw Gubanski (University of Chalmers), and Alun Vaughan (University of Southampton).

Lecturers
J. Fothergill, City University of London, UK
S. Gubanski, University of Chalmers, Sweden
A. Vaughan, University of Southampton, UK
S. Holé, University of Paris 6, France
L. Flandin, University of Savoie-Mont Blanc, France
P. Dufour, University of Toulouse, France
J.-P. Habas, University of Montpellier, France
T. Lebey, CNRS, University of Toulouse, France
P. Nothingher, University of Montpellier, France
G. Teyssèdre, CNRS, University of Toulouse, France
S. Diaham, University Toulouse, France

Thierry Lebey (LAPLACE, left) and Lionel Flandin (University Savoie-Mont Blanc, right) during their lectures with all the attendees.

Practical Work Instructors
S. Agnel, University of Montpellier, France
L. Boudou, University of Toulouse, France
J. Castellon, University of Montpellier, France
J.-C. Laurentie, University of Montpellier, France
L. Laudebat, University of Albi, France
N. Lahoud-Dignat, University of Toulouse, France
Z. Valdez Nava, CNRS, University of Toulouse, France
V. Griseri, University of Toulouse, France
N. Guibert, CNRS, University of Toulouse, France
P. Notingher, University of Montpellier, France
G. Teyssèdre, CNRS, University of Toulouse, France
S. Diaham, University of Toulouse, France

The most specific feature of this Thematic School on Dielectrics was when the attendees were confronted with direct practical situations when they performed specific experimental tasks by themselves.

For that purpose, six experimental setups were brought to the island from LAPLACE and IES Institutes. Characterization techniques covered the different theoretical concepts taught during the lectures. The attendees were trained on dielectric spectroscopy, transient and conduction current measurements, space charge characterization by pulsed electro-acoustic and thermal step methods, and dielectric breakdown and statistical analysis. Each attendee followed a total of eight hours of practical training.

Zarel Valdez-Nava (right) ruling the practical work on dielectric breakdown to Ondrej Sefl (PhD student, TU Prague, Czech Republic), Marie-Laure Locatelli (CNRS Researcher, France), and Silvia De Giovanni (Engineer, Elantas, Italy).
Nicolas Guibert from LAPLACE, one of the instructors for the space charge measurements.
Some PhD students and young engineers working in a group on Weibull data analysis after breakdown tests. They are Simone Suraci (University of Bologna), Hasti Haghighi (University of Manchester), Maria Mitronika (University of Nantes), Kim Yu-Min (Engineer, Hyundai Electric and Energy Systems, South Korea), and Jung-Hun Kwon (Engineer, Power Technology Research, South Korea).

The whole program ended with a two-hour-long general open discussion. It was led by Alun Vaughan and Christian Laurent, who earlier asked the PhD students and postdocs to prepare interesting questions.

Lessons Learned and Future of the School

A questionnaire was distributed among the participants asking for comments regarding school technical content, site facilities, and environment as well as suggestions for improvement. The ability to attend the practical laboratory training was very well acknowledged as the feature of the school, rarely encountered at similar events or forums. As expected, the location was also admired—the experience being strengthened by the sunny weather through the week. Among points for improvement, some comments pointed to the Spartan accommodation. As a site intended mainly for leisure of army staff and their families, comfort is not always a main concern.

Because this Thematic School on Dielectric met well the need of our interdisciplinary research community, its second edition is planned to be organized either in 2020 or 2021. The venue will probably remain the same, Porquerolles Island, because it offers the perfect balance between being convenient to reach and being an isolated study environment. The attendees will have a great opportunity to expand their professional network inside and outside the fields of their specialties. We also hope that IEEE DEIS memberships will again be offered to the registered students.

Jean-Charles Laurentie from IES, one of the instructors for the dielectric spectroscopy measurements.

Acknowledgment

The organizers would like to thank the French Scientific National Research Council (CNRS), the SEEDS French Electrical Engineering Network, the IEEE Dielectric and Electrical Insulation Society (DEIS), and the LAPLACE and IES Institutes for their financial support.

The organizers are very grateful to Odile Bastide, André Bastide, Marc Von Dort, Anne Pontier, Karine Fleurot, and Paul Leblanc for their technical contribution to the event organization.

The organizers also thank all the lecturers and instructors for their contributions to the course program and the practical works on the “insulated island.” Finally, the organizers warmly thank all the participants for coming to share insights on dielectrics.

Sombel Diaham, Petru Notingher, and Gilbert Teyssèdre

Contact information:
S. Diaham, diaham@laplace.univ-tlse.fr
P. Notingher, petru.notingher@umontpellier.fr
G. Teyssèdre, teyssedre@laplace.univ-tlse.fr

More information: https://seedsschool2018.sciencesconf.org/