High Temperature Power Cable Materials and Systems [WG 2023-3]
The conventional insulation systems for cables in the distribution network are today typically based on cross-linked polyethylene (XLPE) or rubbers (EPR/EPDM). The limitation of the highest service temperature to 90 °C for these materials can in some applications impose strong restrictions on operating routines. It can also impede new developments where high temperature (HT) material systems are required.
Recently, extruded fluoropolymer insulated power cable designs have been developed and manufactured to meet the requirements for higher temperature. The conventional XLPE and EPR cable systems have been used for many decades in both land and subsea installations. The electrical ageing and breakdown phenomena for these insulation types have been studied for a long time, and many international cable standards have been developed based on these results. Such knowledge is not readily available for HT materials for e.g. power cable insulation systems. Typical extrudable materials include e.g., fluoropolymers (FEP/PFA), silicone rubbers (SiR) and polypropylene compounds (PPC).
Electrical ageing and breakdown phenomena determine the lifetime of the insulation systems and must be identified to achieve high reliability of the electrical power equipment. The target voltage range is the medium voltage range (6 to and including 36 kV), equivalent to an average electrical stress up to about 5 kV/mm. The knowledge gain from the WG should be used to design new reliable on- and offshore technologies, especially where e.g., high temperature (externally/conductor) or high power is needed, space is restricted, or the components are placed in chemically challenging environments. This could also include
MVDC cables if applicable.
Challenges with regards to cable accessories (joints and terminations) shall also be evaluated.