SuperGrid Institute demonstrates the partial discharge behaviour of SF6 subtitute gases which can be used in the future HVDC GIS as part of the PROMOTioN project

2020-03-04T10:32:39+01:00March 4th, 2020|Event, High Voltage Substation Equipment|

SuperGrid Institute will be able to develop an effective partial discharge monitoring system for the future SF6 free high voltage equipment.

Phd Paolo ERRANTE “Liquid Spray Injection inside the expansion volume of a CO2 High Voltage Circuit Breaker”

2020-02-12T10:22:27+01:00February 5th, 2020|High Voltage Substation Equipment, Phd|

In the framework of the research activities of the High Voltage Substation Equipment program of SuperGrid, it has been proposed to introduce such species by means of an evaporative liquid spray. The interaction between injected droplets and the mixture of hot gases successively flowing into the chamber and vented outside the chamber during the mechanical separation of the electric contacts should allow spray evaporation and transport of the modified gas mixture towards the arc region.

Phd Thibaut LEFORT “Epoxy/ionic liquid networks with and without anhydride: study of polymerization mechanisms and dielectric properties”

2019-12-17T09:08:48+01:00December 12th, 2019|High Voltage Substation Equipment, Phd|

Thursday 12/12/2019, Thibaut Lefort has obtained the title of Doctor of Materials of Lyon university after a high quality viva. Hence, the thesis jury has strongly encouraged him to candidate for a Ph.D award granted by INSA in the energy category.

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.

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

2019-10-25T11:55:04+02:00October 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

Liquid spray injection in the expansion volume of a CO2 high voltage circuit breaker

2019-09-06T14:02:18+02:00September 6th, 2019|High Voltage Substation Equipment, Publications|

Most high voltage gas circuit breakers (HVCB) in operation use SF6 as the arc interruption medium because of its high dielectric strength and good arc interruption properties. However, SF6 also displays a high global warming potential which motivates the investigation of possible alternatives to this gas.