HVDC Air-Core Reactor Charge Dissipation for Particle Control

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Solution Overview

Problem

High-voltage direct current (HVDC) air throttle coils in energy supply networks face issues with particle deposits due to electrical field strengths, leading to 'black spots' that can impair insulation and cause electrical failures, with existing solutions being costly and difficult to manufacture.

Innovation Solution

An HVDC air throttle coil design featuring a hollow cylindrical winding with a spiral-shaped band element made of electrically conductive material attached to the outer surface, connected to the electrical connections, which dissipates electrostatic charges and reduces particle accumulation, allowing for cost-effective and reliable production.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a charge dissipation layer is applied to the outer surface of the winding layer to prevent particle deposits, then the insulation reliability is improved, but the manufacturing complexity and cost increase

Engineering Contradiction:
Improveinsulation reliabilityVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces complex, expensive electrostatic shields with simple, inexpensive band elements made of conductive or semi-conductive material. These band elements are wrapped around the winding layer in a straightforward manner, significantly reducing manufacturing complexity while maintaining the charge dissipation function and preventing particle deposits.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The band elements act as intermediary components that provide a simple connection between the winding layer and the charge dissipation function. Instead of requiring complex integrated electrostatic shields, the band elements serve as intermediate conductive paths that are easier to manufacture and install, thereby reducing overall device complexity while improving insulation reliability.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If an electrostatic shield with dissipative material is used to reduce electrostatic charges, then particle accumulation is prevented, but the processing emissions and environmental impact increase

Engineering Contradiction:
Improveparticle accumulationVSAvoidprocessing emissions
Core Design Contradiction:
Object-affected harmful factorsVSObject-generated harmful factors

Solution Approach 1:

The patent eliminates the need for environmentally problematic spray coatings by using simple band elements that can be wrapped around the winding layer. This approach avoids the processing emissions associated with spray painting while achieving the same charge dissipation effect, thus preventing particle accumulation without generating harmful emissions.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent replaces the chemical/spray-based electrostatic shield application with a mechanical wrapping process. Instead of using spray coatings that generate processing emissions, the band elements are mechanically wrapped around the winding layer, eliminating the harmful emissions while maintaining the charge dissipation function that prevents particle accumulation.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If a spray coating is applied to create the charge dissipation layer, then electrostatic charge dissipation is achieved, but the layer uniformity and seamlessness are difficult to ensure

Engineering Contradiction:
Improvecharge dissipation effectivenessVSAvoidlayer uniformity
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent replaces the difficult-to-control spray coating process with simple band elements that are wrapped around the winding layer. This mechanical approach ensures uniform coverage and seamless construction without the variability inherent in spray coating applications, while maintaining effective charge dissipation.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent substitutes the spray coating mechanical system with a band wrapping mechanical system. The band elements are wrapped around the winding layer in a controlled manner, ensuring uniform distribution and seamless coverage. This mechanical substitution eliminates the precision difficulties associated with spray coating while achieving reliable charge dissipation effectiveness.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 effectively prevents particle deposits on the coil surface, ensuring reliable operation and extended lifespan by dissipating electrostatic charges and maintaining insulation integrity, while being economically viable and easy to produce.

Implementation Method 1

The electrical insulation layer of the choke coil is at least partially provided with a charge dissipation layer, which charge dissipation layer consists of electrically dissipative material. This electrically dissipative material has a predetermined electrical conductivity in order to inhibit the build-up of high electrical charges

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 2

it is proposed to attach an electrostatic shield to the outer surface of the choke coil. This electrostatic shield is formed by a hollow-cylindrical casing for the choke coil

Methodology Applied
Scientific EffectElectrostatic shielding: Faraday Cage

Data Source

PatentEP4179555B1HVDC air-core reactor
Publication Date: 2025.01.29 COIL HLDG
  • EP4179555B1 patent drawingFigure 1
  • EP4179555B1 patent drawingFigure 2
  • EP4179555B1 patent drawingFigure 3

AI summary

The invention relates to an HVDC air-core reactor (1) having at least two electric terminals. Said air-core reactor (1) comprises at least one hollow-cylindrical winding layer (2 - 2"), the electrical conductor wire (17) of which, together with its lateral-surface insulation layer (18), is wound helically around a reactor axis (14), and a charge dissipation layer (20) with a predefined electrical conductivity, which charge dissipation layer (20) is applied at least to an outer lateral surface (21) of the at least one hollow-cylindrical winding layer (2 - 2") and is electrically conductively connected to at least one of the electrical terminals of the air-core reactor (1). The charge dissipation layer (20) comprises at least one first strip element (23) consisting of electrically conductive material, which runs helically around the reactor axis (14) and bears against the outer lateral surface (21) of the at least one hollow-cylindrical winding layer (2 - 2"). The invention also relates to a method for producing such an HVDC air-core reactor (1). An HVDC air-core reactor is thus created with which undesired, field-strength-induced particle deposits can be avoided during active operation and which HVDC air-core reactor can still be constructed as cost-effectively and as functionally reliably as possible.