Upgrading multi-terminal HVDC links using innovative components

The demonstration aims to design, develop and test new technological solutions allowing to upgrade multi-terminal HVDC links.

The planned activities will comprise numerical simulation, design and realization of prototypes or full scale components to be installed in some minor section of the SACOI HVDC intertie. These include Multilevel VSC converter – topologies and control, DC faults management on cable systems, submarine and land cables with extruded insulation compound, High Temperature Low Sag (HTLS) conductors for DC applications and pre-coated Room Temperature Vulcanized (RTV) silicone rebbur cap and pin insulators for DC applications.

The activities are expected to demonstrate that the new HVDC technologies can be implemented in a future HVDC intertie. 

Increasing the knowledge of applicability of VSC convertors to unbalanced bipolar HVDC intertie (implemented with ground return for emergency conditions); Evaluating the extendibility of extruded cables in DC application at voltage higher than 320 kV (today limit) in submarine applications up to 450 m depth. Accessing to the applicability of HTLS conductors for DC application; Improving the performance of DC line insulators; Reducing the outage with a best cable fault location analysis. 

TERNA Rete Italia, RSE, Toshiba T&D Europe, Nexans, De Angeli