Federal Grid of Unified Energy System : Rosseti FGC UES starts building world's largest high temperature superconducting power transmission line

Rosseti FGC UES starts building world's largest high temperature superconducting power transmission line

04/21/2021

The new energy line will connect the main power substations of the Central and Admiralty districts of Saint Petersburg, with more than 400 thousand inhabitants. The project is unrivaled in Russia as well as abroad by length: 2.5 km. With high temperature superconducting (HTSC) direct current cable line, it will transmit up to 50 MW of power at the medium voltage of 20 kV, minimize the losses, boost up reliability and quality of the energy supply.

It is based on developments by R&D Center of Rosseti FGC UES, which were included by the Russian Ministry of Energy into an industry-wide national project. Construction of the HTSC line has several stages: converter unit buildings will be erected on the territory of the 330 kV Tsentralnaya and 110 kV RP-9 substations; the line itself will be built by an open-cut method in an underground trench; trenchless routing is also envisioned by using a directional drilling method. Cable sections will be connected by means of special sleeves, for which sealed monolithic draw-in pits, accessible for service all-year-round, will be installed.

The cost of this project, including the development of the pilot HTSC line and tests at Rosseti FGC UES R&D Center's own test ground, is 3.5 bn rubles. The construction will be finished in 2023.

The key feature of the HTSC line differing it from any existing OHTL is a superconductive material whose resistance vanishes if cooled below 77 K. Because of that, the energy losses in transit are lowered virtually down to zero. The facility includes a dual-circuit cryogenic system 5 km long. That is a unique value as there is no such cooling system anywhere in the world yet.

After some trial operation, the possibility of scaling will be studied. The gained experience will someday allow creating HTSC lines to transmit up to 200 or 300 MW, occupying much less territory than OHTLs of similar throughput capacity do.

The main advantage is that in conditions of dense urban and historical development there is an opportunity to transfer a large power without spoiling the landscape. The power transmission density of HTSC is much higher than that of existing technical solutions, which makes this concept relevant for the dense development of megacities. The technology can also be effective in the construction of ring circuits and power bridges, for the transmission of energy from hydroelectric and nuclear power plants.