Dielectric Materials and Components – High Voltage - HVDC

The electrical energy transmission and high-voltage switchgear design industry is faced with the need to find solutions for insulation constraints. They seek to improve the reliability and lifespan of their components (cables, insulators, circuit breakers, etc.). They are seeking to develop innovative solutions for transport to reduce visual pollution of overhead lines such as high-voltage direct voltage (HVDC) electrical links. To do this, it is therefore necessary to characterize and develop new insulation materials and to take into account environmental constraints.

This teaching unit addresses the different properties of insulating and conductive materials, such as conductivity, permittivity, dielectric break... It defines the theory of the physical origin of the various phenomena related to these properties.

Part of the course is also devoted to measurement techniques, characterizations and data analysis related to the different properties of dielectrics.

This teaching unit also includes a course on the particularities of the use of high voltage as well as applications to high voltage switchgear. It will define the functions, characteristics and constraints of this apparatus.

A presentation of HVDC networks is processed, it gives the architectures of converters and links (unipolar, bipolar), characteristics and constraints.

A practical part including measurements and data analysis for the characterization of dielectrics will be carried out during a mini project.

This course is designed to enable students to join design offices or research laboratories working on the development and characterization of dielectric materials and components.

The aim of this teaching unit is to ensure that, by the end of the course, students are familiar with the properties, limits and uses of conductive and insulating materials.

Students should be able to select materials for common electrical engineering applications (insulating materials, conductors).

The student should be familiar with the physical mechanisms of degradation, understand and predict the modes and mechanisms of material failure, and be able to estimate the lifetime of materials. They should be familiar with the particularities of high voltage (charge injection, ionization, breakdown, etc.).

The student must be familiar with the various high-voltage switchgear used in transmission networks. They will need to know their functions, characteristics and technological limits, so as to be able to make the right choice according to specifications.

The student should be familiar with the architecture, advantages and disadvantages of high-voltage direct current (HVDC) electrical connections.

The basics of electrostatics: coulomb's law, Gauss's law

Recommended prerequisites* :

Physics of materials at the atomic scale, band theory,

Knowledge will be tested by a final exam.

1) Electrical properties

            Matter - Electric field - Potential - Current - Resistivity

            Conductive materials - Insulating materials

            Band theory - Charges - Traps - Conduction mechanisms

            Polarization - Permittivity

            Breakdowns - Breakdown mechanisms

            Reliability of electrical insulators

2) Methods for measuring various properties

            Characteristic current voltage

            Measurement of the breakdown field - Partial discharges

            Space charge measurement

            Dielectric spectroscopy

3) High voltage

            The use of insulating materials under strong electric fields.

            Special features of high-voltage switchgear

4) HVDC networks

            Topology and special features of these networks

CM: 33h