Aluminum Cable Surface Roughness and Oxygen Doping
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Solution Overview
Problem
High-voltage overhead transmission lines experience significant corona effects due to high electric fields, leading to noise, energy loss, and health risks, with existing solutions either costly or insufficient in reducing these issues.
Innovation Solution
An electric current transmission cable with a non-anodized aluminum or aluminum alloy conductor featuring a hydrophilic external surface with increased roughness and deep oxygen doping, reducing the corona effect without increasing weight or section.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the section of the bare conductor is increased to reduce the corona effect, then the corona effect is reduced, but the weight and wind resistance of the cable increase prohibitively
Solution Approach 1:
The invention changes the surface parameters of the conductor by increasing roughness (Ra ≥ 1.9 μm) and applying oxygen doping (≥20% concentration at depth ≥300 nm), which modifies the electric field distribution and reduces corona effect without changing the conductor's cross-sectional area or weight
Solution Approach 2:
The invention applies localized modifications only to the external specific surface of the conductor through roughness treatment and oxygen doping, leaving the bulk material properties unchanged, thus reducing corona effect without increasing overall cable weight
2Object-affected harmful factors
If the section of the bare conductor is increased to reduce the corona effect, then the corona effect is reduced, but the wind resistance of the cable increases prohibitively
Solution Approach 1:
The invention changes the surface parameters of the conductor by increasing roughness (Ra ≥ 1.9 μm) and applying oxygen doping (≥20% concentration at depth ≥300 nm), which modifies the electric field distribution and reduces corona effect without changing the conductor's cross-sectional area or weight
3Object-affected harmful factors
If a semi-conducting polymer sheath is used to cover the bare conductor, then the corona effect is reduced, but the cost and weight of the cable increase significantly
Solution Approach 1:
The invention uses the conductor's own material (aluminum or aluminum alloy) and applies surface treatments (roughness and oxygen doping) to achieve corona reduction, eliminating the need for additional semi-conducting polymer sheaths and their associated costs
Solution Approach 2:
The invention changes the surface parameters of the conductor by increasing roughness (Ra ≥ 1.9 μm) and applying oxygen doping (≥20% concentration at depth ≥300 nm), which modifies the electric field distribution and reduces corona effect without changing the conductor's cross-sectional area or weight
4Object-affected harmful factors
If a hydrophilic plastic sheath is used to cover the bare conductor, then the corona effect is reduced, but the cost and weight of the cable increase significantly
Solution Approach 1:
The invention uses the conductor's own material (aluminum or aluminum alloy) and applies surface treatments (roughness and oxygen doping) to achieve corona reduction, eliminating the need for additional hydrophilic plastic sheaths and their associated weights
5Object-affected harmful factors
If absorbent textile covering is applied to the bare conductor, then the corona effect is reduced, but the cost and bulk of the cable increase significantly
Solution Approach 1:
The invention uses the conductor's own material (aluminum or aluminum alloy) and applies surface treatments (roughness and oxygen doping) to achieve corona reduction, eliminating the need for additional absorbent textile coverings and their associated bulk
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 cable significantly reduces corona effects and associated noise and energy losses by spreading water drops and creating an electronic barrier, achieving a tenfold reduction in noise pollution and line losses without adding materials or reinforcing structures.
Implementation Method 1
having a hydrophilic external specific surface intended to be in contact with the atmospheric medium
Implementation Method 2
spreading water drops on the surface of the conductor in wet weather
Implementation Method 3
an oxygen doping of its components based on aluminum or an alloy of aluminum at a rate greater than or equal to 20%
Implementation Method 4
creating an electronic barrier, achieving a tenfold reduction in noise pollution and line losses
Implementation Method 5
As soon as this electric field becomes locally sufficiently high, in particular greater than the ionization field of moist air, of the order of 10 kV/cm, or even greater than the ionization field of dry air, of the order of 30 kV/cm, the air ionizes producing an electric discharge associated with a characteristic noise, this phenomenon being called corona effect
Data Source
Figure 1~2
Figure 3A~3C
Figure 4A~4C
AI summary
This electric current transmission cable comprises a non-anodized bare conductor (10) based on aluminium or aluminium alloy exhibiting a hydrophilic external specific surface area (S) intended to be in contact with the atmospheric medium and an interior volume (V) intended to conduct an electric current. The external specific surface area (S) of the bare conductor (10) exhibits a first roughness parameter (R), defined as arithmetic mean deviation measureable by profilometry of peaks and troughs with respect to a predetermined mean profile over a reference length or surface, greater than or equal to 1.9 µm. Furthermore, the interior volume (V) of the bare conductor (10) exhibits, down to a depth (P) of at least 300 nm with respect to the external specific surface (S), an oxygen doping of its aluminium-based or aluminium-alloy-based components according to an amount greater than or equal to 20%.