Power transmission systems with cooling mechanisms, and methods of operating the same, are described. A power transmission system can include multiple support tower assemblies. Each of the support tower assemblies includes a support tower. One or more of the support tower assemblies includes a termination (i.e., a connection point via which electrical current and/or coolant can enter the transmission line and/or exit the transmission line). The power transmission system also includes multiple conductor assemblies suspended above a surface of the earth. Each conductor assembly includes an electrical conductor and is positioned between, and mechanically supported by, a pair of the support towers. The power transmission system also includes a coolant supply system that delivers a coolant fluid, during operation of the power transmission system, to at least one of the terminations, for cooling of the conductor assemblies.

Power transmission systems with cooling mechanisms, and methods of operating the same, are described. A power transmission system can include multiple support tower assemblies. Each of the support tower assemblies includes a support tower. One or more of the support tower assemblies includes a termination (i.e., a connection point via which electrical current and/or coolant can enter the transmission line and/or exit the transmission line). The power transmission system also includes multiple conductor assemblies suspended above a surface of the earth. Each conductor assembly includes an electrical conductor and is positioned between, and mechanically supported by, a pair of the support towers. The power transmission system also includes a coolant supply system that delivers a coolant fluid, during operation of the power transmission system, to at least one of the terminations, for cooling of the conductor assemblies.

A superconducting power cable having: a former, a superconducting conductor including a superconducting conductor layer arranged around the former, an insulation layer arranged around the superconducting conductor, a screen arranged around the insulation layer, wherein the screen includes: two concentrically arranged conducting screen layers, wherein at least one of the conducting screen layers is a normal conductor layer arranged to carry fault currents, and an insulating or semiconducting layer arranged between the two conducting screen layers.

A superconducting power cable having: a former, a superconducting conductor including a superconducting conductor layer arranged around the former, an insulation layer arranged around the superconducting conductor, a screen arranged around the insulation layer, wherein the screen includes: two concentrically arranged conducting screen layers, wherein at least one of the conducting screen layers is a normal conductor layer arranged to carry fault currents, and an insulating or semiconducting layer arranged between the two conducting screen layers.

Operational characteristics of an extremely low resistance (ELR) film comprised of an ELR material may be improved by depositing a modifying material onto appropriate surfaces of the ELR film to create a modified ELR film. In some implementations of the invention, the ELR film may be in the form of a c-film. In some implementations of the invention, the ELR film may be in the form of an a-b film, an a-film or a b-film. The modified ELR film has improved operational characteristics over the ELR film alone or without the modifying material. Such operational characteristics may include operating in an ELR state at increased temperatures, carrying additional electrical charge, operating with improved magnetic properties, operating with improved mechanic properties or other improved operational characteristics. In some implementations of the invention, the ELR material is a mixed-valence copper-oxide perovskite, such as, but not limited to YBCO. In some implementations of the invention, the modifying material is a conductive material that bonds easily to oxygen, such as, but not limited to, chromium.

Operational characteristics of an extremely low resistance (ELR) film comprised of an ELR material may be improved by depositing a modifying material onto appropriate surfaces of the ELR film to create a modified ELR film. In some implementations of the invention, the ELR film may be in the form of a c-film. In some implementations of the invention, the ELR film may be in the form of an a-b film, an a-film or a b-film. The modified ELR film has improved operational characteristics over the ELR film alone or without the modifying material. Such operational characteristics may include operating in an ELR state at increased temperatures, carrying additional electrical charge, operating with improved magnetic properties, operating with improved mechanic properties or other improved operational characteristics. In some implementations of the invention, the ELR material is a mixed-valence copper-oxide perovskite, such as, but not limited to YBCO. In some implementations of the invention, the modifying material is a conductive material that bonds easily to oxygen, such as, but not limited to, chromium.

An example electric circuit includes a superconducting component having a first terminal and a second terminal, the superconducting component including a first portion, a second portion, and a third portion electrically connecting the first portion with the second portion. The example circuit also includes an electrically-insulating component that thermally couples the first portion with the second portion such that heat produced in response to the first portion transitioning to a non-superconducting state is transferred through the electrically-insulating component to the second portion. The example circuit further includes an input component coupled to the first portion, the input component configured to supply an input to the first portion, and an output component coupled to the second terminal of the superconducting component, the output component configured to be responsive to a voltage drop across the superconducting component.

An example electric circuit includes a superconducting component having a first terminal and a second terminal, the superconducting component including a first portion, a second portion, and a third portion electrically connecting the first portion with the second portion. The example circuit also includes an electrically-insulating component that thermally couples the first portion with the second portion such that heat produced in response to the first portion transitioning to a non-superconducting state is transferred through the electrically-insulating component to the second portion. The example circuit further includes an input component coupled to the first portion, the input component configured to supply an input to the first portion, and an output component coupled to the second terminal of the superconducting component, the output component configured to be responsive to a voltage drop across the superconducting component.

Apparatus for transmitting electrical energy with a superconducting current carrier, in which the superconducting current carrier to be cooled is accommodated in a first cooling channel, which first cooling channel is connected by way of a coolant feed line to a supply device for a first cooling medium and is surrounded by at least one second cooling channel, for conducting through a second cooling medium, which is flow-connected to a coolant-discharge line for heated second cooling medium, wherein a supercooled, liquefied gas is used as the first cooling medium, is characterized according to the invention in that a liquefied gas is used as the second cooling medium and the second cooling channel is equipped with means for removing a gas phase occurring due to evaporation of the second cooling medium.

Apparatus for transmitting electrical energy with a superconducting current carrier, in which the superconducting current carrier to be cooled is accommodated in a first cooling channel, which first cooling channel is connected by way of a coolant feed line to a supply device for a first cooling medium and is surrounded by at least one second cooling channel, for conducting through a second cooling medium, which is flow-connected to a coolant-discharge line for heated second cooling medium, wherein a supercooled, liquefied gas is used as the first cooling medium, is characterized according to the invention in that a liquefied gas is used as the second cooling medium and the second cooling channel is equipped with means for removing a gas phase occurring due to evaporation of the second cooling medium.