Power Cable Water Blocking Layer via Elastic Support

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional power cables using lead moisture shields are heavy and hazardous due to lead's toxicity, and copper or other harder metals are difficult to shape and reduce in diameter for water barrier applications without risking buckling.

Innovation Solution

A method involving an elastic mechanical support layer around the insulation system, which is compressed and then expanded to support a metallic water blocking layer, eliminating the need for diameter reduction and providing thermal expansion compensation, using materials like polymer foams or tapes for support and compression.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If lead is used for moisture shield, then water protection is provided, but cable weight increases and toxicity hazards arise

Engineering Contradiction:

Improvewater protectionVSAvoidcable weight

Core Design Contradiction:

ReliabilityVSWeight of moving object

Solution Approach 1:

The patent changes the material parameter from lead to copper or other non-toxic metals, and changes the structural parameter by introducing a mechanical support layer. This allows achieving the same water protection function with reduced weight and eliminated toxicity hazards.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite structure combining copper moisture shield with mechanical support layer (polymer foam or tape). This composite approach provides both water protection and mechanical support, replacing the traditional lead shield while reducing weight and eliminating toxicity.

Inventive Principle:

Principle #40Composite materials

2Object-affected harmful factors

If copper or harder metals are used for water barrier, then toxicity is eliminated, but diameter reduction becomes difficult and buckling risk increases

Engineering Contradiction:

ImprovetoxicityVSAvoiddiameter reduction

Core Design Contradiction:

Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

The patent applies preliminary action by providing the mechanical support layer before forming the copper moisture shield. This pre-positioned support prevents buckling during welding and eliminates the need for subsequent diameter reduction operations, making manufacturing easier while using non-toxic copper material.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The mechanical support layer acts as an intermediary between the insulation system and the copper moisture shield. It provides the necessary mechanical support during manufacturing and operation, enabling the use of harder non-toxic metals without buckling issues or complex diameter reduction processes.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Length of stationary object

If diameter reduction is applied to copper sheath, then radial distance is decreased, but buckling occurs and manufacturing difficulty increases

Engineering Contradiction:

Improveradial distanceVSAvoidbuckling

Core Design Contradiction:

Length of stationary objectVSStability of the object's composition

Solution Approach 1:

The mechanical support layer is provided in advance before copper sheet formation and welding. This preliminary support maintains structural stability throughout the manufacturing process, eliminating buckling risks and making the copper sheath formation process straightforward without requiring difficult diameter reduction operations.

Inventive Principle:

Principle #10Preliminary action

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 results in a lighter, safer power cable with reduced risk of buckling and enhanced mechanical properties, maintaining conductor and insulation centering and protection against water ingress, while accommodating thermal expansion.

Implementation Method 1

compressing the mechanical support layer radially by means of a compression element

Methodology Applied

Scientific EffectCompression: Compression

Implementation Method 2

expanding the mechanical support layer by releasing the compression element from compressing the mechanical support layer

Methodology Applied

Scientific EffectElastic recovery: Elastic Recovery

Implementation Method 3

The mechanical support layer can dynamically expand and contract to fill the radial gap/space between the outer semiconducting layer and the metallic water blocking layer as the insulation system thermally expands and contracts in response to the variation in the magnitude of the current

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentEP4293689A1Method of manufacturing a power cable

Publication Date: 2023.12.20 NKT HV CABLES AB

Figure 1~2b
Figure 2c~3

AI summary

A method of manufacturing a power cable, comprising: a) providing a conductor, b) providing an insulation system comprising an inner semiconducting layer arranged around the conductor, an insulation layer arranged around the inner semiconducting layer, and an outer semiconducting layer arranged around the insulation layer, c) providing an elastic mechanical support layer around the outer semiconducting layer, d) compressing the mechanical support layer radially by means of a compression element, e) welding opposing edges of a metallic sheet arranged radially outside of the mechanical support layer longitudinally to form a metallic water blocking layer radially spaced apart from the mechanical support layer in the radially compressed state, and f) expanding the mechanical support layer by releasing the compression element from compressing the mechanical support layer, causing the mechanical support layer to support the metallic water blocking layer.