Patent ID: 6864417

Claim:
A system for transporting electric energy in superconductivity conditions, comprising: a superconducting cable including superconducting material, and a cryogenic plant for cooling said superconducting cable below the critical temperature of said material, comprising: a) a circuit for circulating from and to the superconducting cable a first refrigerating fluid having a first predetermined temperature lower than the critical temperature of the superconducting material, b) a refrigerating circuit for cooling a second refrigerating fluid to a second predetermined temperature lower than the temperature of the first refrigerating fluid, and c) a heat exchange unit for effecting a heat exchange between said first and second refrigerating fluids, said heat exchange unit comprising a storage unit of a third refrigerating fluid having a third predetermined temperature lower than the temperature of the first refrigerating fluid, said third refrigerating fluid being in heat exchange relationship with said first and second fluids, and wherein said storage unit has a predetermined volume adapted to contain a quantity of said third refrigerating fluid at said predetermined temperature, corresponding to the thermal consumption of said superconducting cable for at least two hours in the absence of heat exchange with said second refrigerating fluid.