Direct SC-SC Joint Eliminates Ohmic Losses
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Solution Overview
Problem
Prior art superconducting element joints, particularly plug-in type conductor splices, suffer from high ohmic and cryogenic losses, which accumulate in long cables and are challenging to manage, especially in DC cables where ac losses are significant, and they introduce complexity in manufacturing and utilization.
Innovation Solution
A direct SC-SC transition joint with a staggering arrangement that reduces ohmic and cryogenic losses by eliminating intermediate non-superconducting sections, allowing for strong mechanical strength, high current rating, and fault current capabilities, while maintaining a slim cable design and efficient thermal load distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a plug-in type conductor splice with intermediate non-superconducting sections is used, then the joint structure is simpler to manufacture, but ohmic and cryogenic losses increase significantly
Solution Approach 1:
The invention removes the intermediate non-superconducting sections (Cu, Al, or composite inserts) from the joint structure, creating a direct superconductor-to-superconductor connection. This extraction eliminates the source of ohmic losses and reduces cryogenic losses by eliminating thermal interfaces between dissimilar materials, directly resolving the energy loss problem while maintaining manufacturing feasibility through simplified joint geometry
Solution Approach 2:
Instead of using a normal conductor insert as the core element with superconductors attached (prior art approach), the invention inverts the structure by making the superconducting elements directly contact each other without any normal conductor intermediary. This inversion fundamentally changes the joint architecture to eliminate resistive losses at the interface
2Power
If multiple conductor joints are introduced to connect superconducting elements, then the current transmission capability is maintained, but the complexity of the joint structure increases
Solution Approach 1:
The invention merges multiple conductor joints into a single integrated direct SC-SC transition joint structure. By combining the functions of multiple separate joints (each requiring inserts, insulation, and connection elements) into one unified superconductor-to-superconductor interface, the design maintains full current transmission capability while dramatically reducing structural complexity and the number of manufacturing steps
3Strength
If extended ohmic transition sections are used in Cu transition pieces, then the mechanical strength of the joint is improved, but the ohmic losses accumulate and become significant
Solution Approach 1:
The invention extracts and removes the extended Cu transition pieces and ohmic transition sections from the joint design. By eliminating these normal conductor sections entirely, the design achieves direct superconducting contact that maintains mechanical strength through proper superconductor-to-superconductor bonding while completely eliminating the source of ohmic losses that would otherwise accumulate in extended transition sections
4Loss of energy
If forced cooling is applied to reduce ohmic losses, then the energy efficiency is improved, but the cryogenic losses and cooling requirements increase
Solution Approach 1:
The invention converts the harmful ohmic losses (which would require forced cooling to mitigate) into a non-existent problem by eliminating the resistive interfaces entirely. By creating direct superconducting contacts with zero resistance, the design achieves inherent loss-free current transmission without requiring any additional cooling infrastructure, thereby reducing both ohmic losses and the associated cryogenic energy consumption
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution significantly reduces ohmic and cryogenic losses, maintains or improves mechanical strength and current handling capabilities compared to virgin cables, and allows for efficient cooling and reduced bulkiness, making it suitable for long cable systems.
Implementation Method 1
A direct SC-SC transition joint, where SC means superconducting, is provided between two joining ends of superconducting elements
Data Source
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AI summary
The invention relates to a superconducting element joint comprising a joint between two superconducting elements comprising at least one direct SC- SC transition joint. By the invention an improved superconducting element joint may be obtained. The invention also relates to a process for providing such superconducting element joint and a superconducting cable system comprising such superconducting element joint.