Prysmian, a global leader in cable solutions for the energy transition and digital transformation, needed to select the best materials combination for its brand new HVDC epoxy-insulated cable terminations. These terminations are a complex arrangement of materials that ensure the safe connection of HVDC cables to GIS. Understanding how they interact with SF6 alternative gases was also necessary. For this project, multiple epoxy samples were tested simultaneously under different conditions including humidity, temperature & voltage stresses.  

Although cable termination are complex, they are crucial  for connecting HVDC cables to HVDC Gas Insulated Switchgear (GIS). Why complex? Because they combine several material assemblies that must work reliably in close contact. This means that physical processes must be taken into account in order to predict the electric field distribution under all operating conditions, including transient conditions. That’s why all the insulation materials and the interfaces in the accessory must be carefully studied.

In addition, the GIS’s gaseous insulation is in direct contact with both the metallic components and epoxy insulation, making material selection, both the insulating gas and the epoxy composite, critical to achieving very high voltages, up to the targeted 640 kV DC in this case.

Thanks to our state-of-the-art testing platforms and our expertise in solids & gases, we are proud to have supported Prysmian in this development by providing a comprehensive set of data covering  9 material combinations. Prysmian was able to pursue its ambitious R&D roadmap and achieve its goal of becoming SF₆-free. This has enabled the company to take the lead in meeting the increasingly complex demands of the HVDC market.

The interface between epoxy and gas is one of the most challenging to manage. This work resulted in a joint publication presented at Jicable’23: “Characterization and modelling of interface between Epoxy Resin materials and different gases for HVDC GIS cable termination development”.

We are delighted to count Prysmian among our regular customers and to assist them in their development and innovation efforts!

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