Superconducting direct current transmission system

摘要

A DC superconducting coaxial transmission system provides electrical transmission of 5,000 megawatts of energy while simultaneously delivering liquid hydrogen. The transmission system includes a coaxial transmission segment including an inner superconductor, an outer superconductor disposed in surrounding relation to the inner conductor, and a dielectric insulator disposed between the inner superconductor and the outer superconductor. Liquid hydrogen surrounds the superconductors. Three phase transformers and poly phase rectifier/inverters provide a DC voltage source to the superconductors from the electrical grid. In one embodiment, a switching circuit connected between the voltage source and the superconductor injects a cancellation current component into the direct current flow. The cancellation current component is polarized to flow in a direction opposite to the direct current flow to produce a current zero, thus enabling safe interruption of the high DC current while minimizing the magnitude of transient voltages during switching.

主权项

1. A direct current coaxial superconducting transmission segment, comprising:
a cylindrical inner superconductor defining a core, the core adapted to flow a first coolant medium; a vacuum dielectric insulator disposed in surrounding relation to the inner superconductor; an outer superconductor disposed in surrounding relation to the insulator; a cylindrical housing disposed in surrounding relation to the outer superconductor, the housing defining a containment adapted to flow a second coolant medium; a thermal insulation barrier disposed in surrounding relation to the housing; and an electrical insulation layer disposed in surrounding relation to the thermal insulation barrier and a stainless steel protective outer shell disposed in surrounding relation to the electrical insulation layer.