Another potential use of HTS power cable is to improve grid power transmission by connecting two existing substations. In dense urban environments many substations often reach capacity limits and require redundant transformer capacity to improve reliability. HTS cables can tie these existing stations together, avoiding very costly transformer upgrades and construction costs.
What is an HTS Power Cable?
Constructing superconducting high power transmission cable requires a great deal more HTS wire than one might expect. Independent of the design, each cable type contains hundreds of strands of layered HTS wire. Strands of HTS wire are wound around a core in a one direction and then the next layer is wound in the opposite direction. This process is repeated many times. Cable manufacturers use more than 400 kilometers of HTS wire (4mm wide @ 90 A/cm) to construct a single kilometer of superconducting power cable.
There are several unique configurations utilized to construct an HTS power cable. One superconducting cable design is the Triax. This proprietary configuration winds three phases concentrically on a single inner copper core. This superconducting cable design integrates each AC phase into a single cable stacked on top each other. A second cable design consists of three separate, single-phase, cables encapsulated in a single cryogenic envelope. A third type of HTS cable uses three individual, single-phase cables, with each encapsulated in an individual cryogenic envelope.