Twisted Superconducting Cable for Aircraft Weight Reduction

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Solution Overview

Problem

Superconducting cables with twisted structures face challenges in uniform current distribution, increased weight due to copper formers and thick insulating layers, and complexity in manufacturing and installation, particularly for aircraft applications where high voltage is not feasible, leading to a need for a lightweight, high-current cable with improved bending and installation capabilities.

Innovation Solution

A method involving a twisted superconducting cable structure with layers of tape wires, where current lead wires connected to room temperature portions are electrically insulated and have nested polarity connections, utilizing thermoelectric semiconductors for heat transfer via the Peltier effect, and a thermally insulated double pipe with a refrigerant buffer to maintain refrigerant levels, facilitating uniform current flow and easy bending.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a copper former is used at the central portion of the superconducting cable, then the structural integrity is improved, but the weight of the cable increases

Engineering Contradiction:

Improvestructural integrityVSAvoidcable weight

Core Design Contradiction:

StrengthVSWeight of moving object

Solution Approach 1:

The patent removes the copper former from the cable structure, replacing it with a stack conductor composed of multiple layers of superconducting tape wires. This extraction of the heavy copper component directly addresses the weight reduction goal while maintaining structural integrity through the alternative stack conductor design.

Inventive Principle:

Principle #2Taking out (Extraction)

2Reliability

If an electrically insulating layer is made thick for high voltage use, then the electrical insulation performance is improved, but the weight of the cable increases

Engineering Contradiction:

Improveelectrical insulation performanceVSAvoidcable weight

Core Design Contradiction:

ReliabilityVSWeight of moving object

Solution Approach 1:

The patent changes the voltage parameter from high voltage to low voltage (below 1 kV), which is suitable for aircraft applications. This parameter change allows for a reduced insulating layer thickness, thereby reducing cable weight while maintaining adequate electrical insulation performance for the lower voltage level.

Inventive Principle:

Principle #35Parameter changes

3Ease of operation

If a stack conductor is twisted with certain pitches, then the bending capability is improved, but the manufacturing complexity increases due to thermal contraction differences

Engineering Contradiction:

Improvebending capabilityVSAvoidmanufacturing complexity

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The patent segments the cable into distinct functional portions: a straight portion for normal current transmission and a bent portion with twisted stack conductor for routing flexibility. This segmentation allows the twisting operation to be localized only where bending is needed, reducing the overall manufacturing complexity while maintaining bending capability where required.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent performs the twisting operation on the stack conductor before cooling it to the superconducting state. This preliminary action is taken at room temperature where thermal contraction has not yet occurred, allowing for easier manipulation and alignment. The twisting is then locked in place before the thermal contraction phase, avoiding the complexity of accommodating differential shrinkage during the twisting process.

Inventive Principle:

Principle #10Preliminary action

4Weight of moving object

If the cable length is kept short (within 200 m) for low voltage applications, then the weight is reduced, but the adaptability for various installation scenarios decreases

Engineering Contradiction:

Improvecable weightVSAvoidinstallation adaptability

Core Design Contradiction:

Weight of moving objectVSAdaptability or versatility

Solution Approach 1:

The patent introduces dynamic flexibility to the cable system by enabling the stack conductor to be twisted at specific portions. This creates a semi-rigid structure that can adapt its shape through localized twisting operations, providing installation versatility comparable to longer cables while maintaining the weight advantages of shorter cable lengths.

Inventive Principle:

Principle #15Dynamics

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

Enables uniform current flow through tape wires without transposing them, reduces weight and complexity, and allows for efficient hydrogen gas production, making the cable suitable for aircraft applications with improved bending and installation characteristics.

Implementation Method 1

utilizing thermoelectric semiconductors for heat transfer via the Peltier effect

Methodology Applied

Scientific EffectPeltier effect: Peltier Effect

Implementation Method 2

thermally insulated double pipe with a refrigerant buffer to maintain refrigerant levels

Methodology Applied

Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 3

superconducting cable

Methodology Applied

Scientific EffectSuperconductivity: Superconductivity

Data Source

PatentUS11482353B2Superconducting cable and installation method of the same

Publication Date: 2022.10.25 CHUBU UNIVERSITY EDUCATIONAL FOUNDATION

AI summary

When bending a superconducting cable of a stack conductor structure in which a plurality of layers of tape wires are stacked, a twisting process is performed for the superconducting cable immediately before a bending portion of the superconducting cable.