Tapered Superconducting Wire Connection Structure

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional superconducting wire connection methods lead to current flow concentration due to the skin effect, causing heat and deterioration of the superconducting layer, and are impractical for on-site applications or wires with non-removable surface metal layers.

Innovation Solution

A superconducting wire connection structure where tape-shaped wires with uniform widths and a substrate-laminated superconductive layer are connected by a third wire that tapers and is narrower than the connecting wires, with a solder layer ensuring stable superconductivity and reduced heat generation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a connection superconducting wire is used to join superconducting wires by soldering or spot welding, then electrical connection is achieved, but current flow concentration occurs around ends of the connection superconducting wire due to skin effect, causing heat and deterioration of the superconducting layer

Engineering Contradiction:
Improvesuperconductivity stabilityVSAvoidcurrent flow concentration and heat generation
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The connection superconducting wire is designed with non-uniform width, being narrower at its ends and wider in its intermediate portion. This local variation in geometry distributes the current flow more evenly along the wire, preventing concentration at the ends where skin effect would otherwise cause excessive current density and heat generation.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The width parameter of the connection superconducting wire is changed along its length, creating a tapered profile at the ends. This parameter change optimizes the current distribution by reducing the cross-sectional area at the ends where current concentration occurs, thereby reducing current density and heat generation in those critical regions.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If a superconducting film is deposited on the connection portion or surface metal layer is removed and redeposited, then connection is achieved, but it is hard to bring a deposition apparatus to a work site when adopted to applied apparatus

Engineering Contradiction:
Improveconnection stabilityVSAvoidon-site applicability
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The connection superconducting wire is pre-formed with the optimal non-uniform width profile and ready-to-use configuration before reaching the work site. This preliminary preparation eliminates the need for on-site deposition apparatus or complex processing steps, allowing workers to simply install the pre-fabricated connection wire at the connection location.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The complex deposition process and apparatus are extracted from the on-site operation and replaced with a pre-fabricated connection wire that has already undergone the necessary manufacturing processes in a controlled environment. This separates the complex manufacturing steps from the simple installation task performed on-site.

Inventive Principle:
Principle #2Taking out (Extraction)

3Ease of manufacture

If surface metal layer is removed to join connection superconducting wire, then connection is achieved, but superconductivity may be lowered by removal of the surface metal layer

Engineering Contradiction:
Improveconnection easeVSAvoidsuperconductivity
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The connection superconducting wire is pre-prepared with its superconductive layer and surface metal layer already in place during manufacturing. This preliminary preparation ensures that the wire maintains its full superconducting capability throughout the connection process without requiring removal of protective or functional layers at the connection site.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The connection superconducting wire is designed to serve multiple functions simultaneously: it provides electrical connection, maintains superconductivity, and preserves its surface metal layer for protection and current carrying capability. This multi-functionality eliminates the need to compromise superconductivity for connection purposes.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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

This method allows for easy and stable superconductivity connections by reducing current density and heat generation at the connection points, preventing deterioration of the superconducting layer and enabling on-site applications with various wire types.

Implementation Method 1

a solder layer which connects the first superconducting wire, the second superconducting wire and the third superconducting wire

Methodology Applied
Scientific EffectSoldering: Soldering

Data Source

PatentEP2728592B1Superconducting wire connection structure, superconducting wire connection method, and use of connection superconducting wire
Publication Date: 2019.09.18 FURUKAWA ELECTRIC CO LTD
  • EP2728592B1 patent drawingFigure 1~2
  • EP2728592B1 patent drawingFigure 3~5
  • EP2728592B1 patent drawingFigure 6~7

AI summary

A superconducting wire connection structure is adopted in which, in a section where the ends of a first superconducting wire (11) and a second superconducting wire (12) are spaced apart from and arranged across from each other, the third superconducting wire (13), which is narrower in at least one portion than the first superconducting wire (11) and the second superconducting wire (12), spans and connects the first superconducting wire (11) and the second superconducting wire (12) along the longitudinal direction of the first superconducting wire (11) and second superconducting wire (12) . Thereby, it is possible to reduce degradation of the superconducting layer (3) by suppressing generation of heat caused by current flow concentration at the section where the third superconducting wire (13) is connected, and stable superconducting performance can be achieved.