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Françoise Lamnabhi-Lagarrigue has been awarded the Irène Joliot-Curie 2019 Prize in the Female Scientist of the Year category

2020-01-20T17:23:30+01:00November 27th, 2019|Event, Supergrid Architecture & Systems|

Françoise Lamnabhi-Lagarrigue has been awarded the Irène Joliot-Curie 2019 Prize in the Female Scientist of the Year category. Congratulations to Françoise for this acclaimed recognition of her work!

SuperGrid Institute’s “Technical days”: an event dedicated to our industrial shareholders

2019-11-22T09:48:26+01:00November 22nd, 2019|Event|

SuperGrid Institute has held its first ever ‘Technical days’ event! Dedicated to our industrial shareholders, this event was organised to facilitate exchange and to allow us to better adapt our roadmap to the industry’s tangible needs. These two exciting days of workshops, discussions and networking have bolstered our belief in the importance of our mission to shape tomorrow’s HV & MV power transmission grids.

Design and validation tests of 320kV HVDC GIL/GIS

2019-11-22T11:15:42+01:00November 21st, 2019|High Voltage Substation Equipment, Publications|

This paper gives an overview of electrical DC phenomena in GIL/GIS, the influence of insulating properties of SF6 and filled epoxy resin, and design of new support insulator for 320kV HVDC GIL/GIS. The busbar system including the insulator was designed not only to satisfy all standard requirements such as mechanical, temperature rise, heating cycle performance but also particular requirements for HVDC applications such as superimposed impulse tests. Finally and for the first time at actual scale, type test according to CIGRE JWG D1/B3.57 was conducted in EDF R&D Les Renardières laboratory to verify the design and insulating performance of the 320kV HVDC GIL/GIS system. The satisfactory results allow to confirm the high technology readiness level of HVDC GIL/GIS.

Phd Raphael CHASSAGNOUX “Dielectric study of liquid and boiling nitrogen – Application to a superconducting fault current limiter”

2019-11-15T15:23:07+01:00November 14th, 2019|High Voltage Substation Equipment, Phd|

The increasing number of interconnections in electrical networks and the massive integration of renewable energies nowadays comes with an increase of short circuit currents, and more constraints on high voltage circuit breaker during the current clearance. To solve this problem, a solution consists in inserting a fault current limiting device on electrical lines. Among the available technologies, the superconducting fault current limiter is ideal from the perspective of transmission system operator. However the design of this device is non-trivial, especially the electrical insulation, which is very specific to this apparatus: electrical insulation in a cryogenic environment (liquid nitrogen at - 196°C), superconducting tapes inducing electric field reinforcement, and strong transient heating generating numerous vapor bubbles.

Phd Alexis FOUINEAU “Medium Frequency Transformers design methodologies for high voltage grids and railway grids”

2019-11-15T15:20:17+01:00November 13th, 2019|High Voltage Substation Equipment, Phd|

Medium Frequency Transformers (MFT) are an innovative technology compared to low frequency transformers, with the promise of reduced volume and increased efficiency. This PhD thesis focuses in particular on their design for high voltage, high power applications, such as high voltage and medium voltage DC networks, as well as railway networks. In these applications, MFTs are used in converters that can generate specific constraints to be taken into account during their design: non-sinusoidal signals, polarization voltage, target inductance values.

A DC voltage source for long term GIS testing designed by SuperGrid Institute

2019-11-07T17:32:54+01:00October 29th, 2019|High Voltage Substation Equipment|

As part of its research, SuperGrid Institute studies the phenomena of partial discharge under DC voltage. Environmental issues emphasised in the European project PROMOTioN encourage the exploration for possible replacement of SF6 gas and remains a strong component of the study at SuperGrid Institute.

NPC assessment in insulated DC/DC converter topologies using SiC MOSFETs for Power Electronic Traction Transformer

2019-10-22T11:34:14+01:00October 24th, 2019|Power Electronics & Converters, Publications|

Power electronic traction transformers (PETT) are multilevel AC/DC on-board converters, studied for railway applications to replace traditional solution with low frequency transformers. This paper focuses on the insulated DC/DC converter in a PETT. Three variants of resonant single active bridges (R-SAB) with 3-level NPC primaries are optimised to maximise the efficiency, under mass and dimension constraints. They are sized and compared for a 2 MW PETT on a 15 kV/16.7 Hz railway infrastructure, using 3.3 kV SiC MOSFETs and nanocrystalline C-core transformers with cast resin insulation and forced air cooling. The highest efficiency at nominal power, 99.17 %, is reached for a configuration with a 3-level full bridge NPC primary, a 2-level full bridge secondary, and a 32.1 L/49.1 kg transformer operating at 6 kHz.

The renewables integration via HVDC grids

2019-10-28T08:59:10+01:00October 22nd, 2019|Supergrid Architecture & Systems|

The large-scale integration of renewable electricity generation poses both structural, economic and management challenges. Among the major challenges, one can note the grid integration and the routing of this energy from the production units to the consumption poles. Major issues have to be faced like insufficient transmission capability, inertia reduction, stability margins mitigation. The HVDC is not a new idea but it can provide some interesting answers to these challenges. The keynote will list the locks and how they can be addressed by the HVDC grid. Finally, the underlying scientific issues will be discussed.

Electric field computation for HVDC GIS/GIL spacer under superimposed impulse conditions

2019-10-25T11:55:04+01:00October 21st, 2019|High Voltage Substation Equipment, Publications|

This paper evidences the influence of different parameters on the electric field on DC spacers in GIS/GIL and thus their dielectric withstand under S/IMP tests. A notable difference in term of electric field can be observed in function of impulse polarity, load condition (with/without heating current) and insulating material’s properties. For example, an overstress of 0.3pu was obtained on spacer’s surface in case of superimposed impulse test with opposite impulse polarity, high load condition and high leakage current in gas. Contrary to AC system where the simple LI tests were enough, S/IMP tests with both impulse polarity, ZL and HL conditions are mandatory to verify the insulating performance of HVDC GIS/GIL spacer. This paper gives a better understanding of the electric field distribution in HVDC GIS/GIL and helps for the design and tests

Phd Guilherme DANTAS DE FREITAS “Development of a methodology for DC grid protection strategies comparison”

2019-10-22T18:15:05+01:00October 18th, 2019|Phd, Supergrid Architecture & Systems|

High Voltage Direct Current (HVDC) grids are considered a promising solution for problems faced by nowadays power system such as: lines congestion, integration of large amounts of renewable power and enhancement of AC system stability. Among the challenges in the deployment of a HVDC meshed grid, the protection of these grids is regarded as one of the most critical. The protection of HVDC grid is challenging not only because the swift transients and fault currents without zero-crossing, but also due to the impact a DC faults can have on the AC system. Several propositions for HVDC grids protection strategies can be found in literature...