Current and future applications of HPTE insulated cables systems

HPTE insulated cables represent an attractive alternative to traditional cables insulated with crosslinkable materials. Thanks to a set of advantages, mainly due to the use of thermoplastic PP based insulation, superior performances can be achieved for cables with HPTE insulation. After an important experience in the field of MV cables, now HPTE insulation is being extended to HVAC and HVDC areas. In the field of HVAC, a cable length (1000 mm2 Cu 150 kV with HPTE insulation) has been installed in the Italian Transmission network and is in service since 2013. In HVDC important qualifications have been achieved in 320 kV, 350 kV and recently 600 kV voltage class, at high conductor temperature (90°C) and including both VSC and LCC typology. These results have been obtained thanks to an extensive work performed on materials development and technological improvements, for cables and accessories. The paper describes the developments performed and the results achieved, that are very promising especially in view of possible applications of HPTE insulated cables for EHVDC systems.