High Voltage Underground Cables

In a world of rapidly rising demand, electric power distributors are being challenged to develop high voltage (HV) networks faster and more economically, while at the same time improving supply quality. 

Traditionally, overhead lines have been preferred as the lower cost choice to meet these needs.  Today, however, advances in crosslinked polyethylene (XLPE) insulation mean that HV underground cable networks achieve a lower total-system cost to be a fully competitive alternative.  Moreover, they bring additional advantages in both performance and environmental acceptance. For the power distributor, HV underground cable networks deliver:

• faster installation;
• environmental invisibility;
• low energy losses;
• improved transmission reliability;
• reduced risk of network failure.

Cleanliness ensures good electrical performance

To help cable makers meet the needs of their customers, Borealis has developed a family of Superclean™ XLPE insulation compounds designed for high voltage applications. Contamination-free production and delivery in Superclean octabins, which are filled and emptied under clean room conditions, Superclean insulation compounds provide:

• the highest level of cleanliness;
• reduced risk of degradation by contaminants;
• consistent performance, long-term reliability.

Importantly for the cable maker, Superclean aids manufacturing through better scorch safety, longer production runs before equipment needs to be cleaned, a lower degassing burden, and shorter production cycles by 10-20%.

Semiconductive screen materials add value to HV cable

At higher electrical stresses a smooth interface between insulation and shielding increases the potential for reliable, uninterrupted power supply.  Borealis’ Supersmooth™ semiconductive materials have been optimised to provide the semiconductive layers on both sides of the Superclean XLPE insulation with very smooth and even surfaces.  Supersmooth:

• eliminates surface pips;
• reduces electrical stresses,
• minimises the risk of power failure.