Wind Turbine Tower Cable Shielding via Flexible EMC Element

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Solution Overview

Problem

Existing electromagnetic shielding solutions for wind turbine towers fail to effectively attenuate electromagnetic radiation across a wide frequency range while allowing for mechanical movements during operation, such as yawing and pendular movements, without compromising the integrity of the shielding.

Innovation Solution

A two-part cable ducting arrangement with a rotatable ring and cover connected by a flexible, electromagnetic radiation-impermeable element, which establishes an electrical connection through a slip apparatus, ensuring continuous shielding even during mechanical loads and movements, and includes features like clamping rings and suspension brackets to maintain effective shielding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If rigid shielding structures are used to ensure electromagnetic shielding effectiveness, then shielding performance is improved, but the structure cannot accommodate mechanical movements during wind turbine operation

Engineering Contradiction:
Improveelectromagnetic radiation attenuationVSAvoidmechanical movement capability
Core Design Contradiction:
Object-affected harmful factorsVSAdaptability or versatility

Solution Approach 1:

The patent employs a flexible shielding element made of conductive material that can bend and deform while maintaining its electromagnetic shielding properties. This flexible element is positioned between the cover and ring, allowing it to accommodate relative movements between these components during wind turbine operation while continuously blocking electromagnetic radiation from the cables.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The shielding structure is designed with movable and flexible components rather than rigid fixed connections. The cover can rotate relative to the ring, and the flexible shielding element dynamically adjusts its position to maintain continuous electromagnetic shielding coverage despite changes in the relative positions of the tower, nacelle, and cable loop during operation.

Inventive Principle:
Principle #15Dynamics

2Stability of the object's composition

If the cover and ring are directly connected to maintain structural integrity, then mechanical stability is improved, but electromagnetic radiation can leak through gaps during relative movements

Engineering Contradiction:
Improvestructural stabilityVSAvoidelectromagnetic radiation leakage
Core Design Contradiction:
Stability of the object's compositionVSObject-affected harmful factors

Solution Approach 1:

A flexible shielding element made of conductive material is positioned between the cover and ring. This element maintains continuous electromagnetic shielding coverage even when the cover and ring move relative to each other, preventing radiation leakage through gaps while allowing the necessary mechanical movement for wind turbine operation.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The flexible shielding element acts as an intermediary component between the cover and ring. It fills the intermediate space and maintains continuous electromagnetic shielding coverage even when the cover and ring move relative to each other, preventing radiation leakage through gaps while allowing the necessary mechanical movement.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If fixed cable routing is used to simplify the structure, then device complexity is reduced, but the nacelle and rotor cannot yaw for changing wind directions

Engineering Contradiction:
Improvecable routing structureVSAvoidyaw capability
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The cable ducting arrangement is designed with a rotatable cover that can rotate relative to the ring, and the flexible shielding element accommodates this rotation. This dynamic structure allows the nacelle and rotor to yaw for changing wind directions while maintaining continuous electromagnetic shielding coverage throughout the movement range.

Inventive Principle:
Principle #15Dynamics

4Adaptability or versatility

If the intermediate space between cover and ring is left open to allow movement, then mechanical flexibility is improved, but electromagnetic radiation leaks through the gap

Engineering Contradiction:
Improvemechanical flexibilityVSAvoidelectromagnetic radiation emission
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The flexible shielding element is positioned to cover the intermediate space between the cover and ring. It maintains continuous electromagnetic shielding coverage even when the cover and ring move relative to each other, preventing radiation leakage through the gap while allowing the necessary mechanical flexibility for wind turbine operation.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The flexible shielding element acts as an intermediary that fills and seals the intermediate space between the cover and ring. It prevents electromagnetic radiation from leaking through the gap while allowing the cover and ring to move relative to each other during wind turbine operation.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 provides comprehensive electromagnetic shielding across a broad frequency range, including 1-500 MHz, while allowing for operational movements without compromising the integrity of the shielding, thereby reducing electromagnetic interference and ensuring efficient energy transmission.

Implementation Method 1

a flexible element (32), in particular an EMC textile nonwoven fabric, which connects the cover (22) to the ring (34) and closes an intermediate space (26) between these

Methodology Applied
Scientific EffectElectromagnetic shielding: Faraday Cage

Implementation Method 2

the ring (34) is equipped with a slip apparatus which, even during a rotation of the ring (34), establishes an electrically conducting connection to the base fixed to the tower

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP3751134B1Device for electromagnetic shielding in a tower of a wind turbine
Publication Date: 2022.04.27 NORDEX ENERGY SE & CO KG
  • EP3751134B1 patent drawingFigure 1
  • EP3751134B1 patent drawingFigure 2
  • EP3751134B1 patent drawingFigure 3

AI summary

A device for electromagnetic shielding in a tower of a wind turbine, which has a platform closing the inside of the tower having an aperture for one or more cables, wherein a cable ducting arrangement is provided, which can pivot relative to the tower with the cable or cables, wherein a. the cable ducting arrangement has a rotatably arranged ring and a cover with one or more cable openings, b. the ring encloses the aperture of the platform and rests on a base fixed to the tower, c. a flexible element which is not permeable or only poorly permeable to electromagnetic radiation connects the cover and the ring, d. wherein the ring has a sliding apparatus which establishes an electrically conducting connection of the ring to the base fixed to the tower.