Extra High Voltage Cables
Crosslinked polyethylene (XLPE) has become the preferred insulation for high voltage (HV) underground cables. Its high reliability, cost effectiveness, low dielectric losses and low environmental impact are recognised as its main advantages. Voltage ratings of cables have been increasing and as a result there is more electrical stress on the XLPE compound. So-called extra high voltage (EHV) cables, operating above 220kV, require insulation systems with an even better performance.
Borlink™ XLPE compounds
Borouge and Borealis offer Borlink™ XLPE insulation compounds for extra high voltage cable insulation. Borlink™ XLPE is a range of materials that provide a significantly improved performance, compared to those used for high voltage cables.
Cleanliness essential to performance
The reliability of a cable system of course depends on the correct design and careful manufacturing practices. But equally important is the use of high quality, clean XLPE compounds. If the insulation of a cable is contaminated, the performance of the insulation goes down under high electrical stresses, possibly even leading to a system failure. The highest level of material cleanliness minimises these potential hazards.
Borlink™ XLPE compounds provide for:
- Exclusion of contaminants >100µ
- Control of contaminants < 70µ
- Very clean and consistent quality materials
Dedicated clean delivery system
The cleanliness that is achieved during production is preserved during transportation to cable extrusion plants by packing the Borlink™ materials in EHV Octabin containers, that were developed by Borealis. These tailored containers are filled and emptied under clean room conditions.
Borlink™ XLPE compounds offer cable makers several key manufacturing advantages:
- Better scorch safety
- Longer intervals between cleaning - longer production runs
- Lower degassing burden
- 10-20% shorter production cycles
Borlink™ semiconductive screen improves EHV cable
Extra high voltage cables experience elevated electrical stresses. A smooth interface between the insulation and shielding layers acts as a semiconductive screen, minimising the risk of power interruptions. Borouge’s Borlink™ creates a smooth surface on both sides of the Borlink XLPE insulation material, optimising the reliability and lifetime of the cable by:
- Eliminating surface pips
- Reducing electrical stresses