Multi-phase Cable Conductor Arrangement for Skin Effect Reduction
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Solution Overview
Problem
Multi-phase cables face reduced ratings due to bundling effects, skin effects, and proximity effects, which limit their ability to carry high-frequency currents effectively, leading to increased ohmic losses and inefficiencies.
Innovation Solution
The cable design features conductors with cross-sectional dimensions sized to minimize skin effects and arranged in a single layer for improved convection and reduced proximity effects, allowing each conductor to be cooled by free air from multiple sides and reducing ohmic losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If multiple wires are bundled together to increase current capacity, then the total cross-sectional area increases, but the cable rating decreases due to reduced convection cooling
Solution Approach 1:
The patent transitions from traditional multi-layer bundled cable structures to a single-layer flat cable configuration. This dimensional reorganization allows each conductor to be exposed to free air on multiple sides, restoring convective cooling efficiency while maintaining high current capacity through increased total cross-sectional area of conductors in the single layer.
2Quantity of substance
If conductor size increases to carry higher current, then current capacity improves, but skin effect increases causing higher ohmic losses
Solution Approach 1:
The patent divides the current-carrying function across multiple individual conductors within the single layer rather than using fewer large conductors. This segmentation maintains high total current capacity while keeping each individual conductor's cross-sectional dimensions small enough to minimize skin effect and associated ohmic losses at high frequencies.
3Device complexity
If conductors of the same phase are placed adjacent to each other for compact arrangement, then cable structure simplifies, but proximity effect increases forcing currents to flow on outer surfaces
Solution Approach 1:
The patent implements a phased arrangement where conductors of the same phase are separated by conductors of different phases within the single layer. This local differentiation in phase positioning reduces proximity effects between adjacent conductors of the same phase, allowing more uniform current distribution across conductor surfaces and reducing ohmic losses.
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
This configuration enhances the cable's current-carrying capacity, reduces ohmic losses, and increases the cable rating, enabling efficient high-frequency current transmission with potential size and weight reductions.
Implementation Method 1
each conductor having a cross-section with at least one dimension that is sized to decrease a skin effect of the conductor at a maximum or nominal operation frequency of the conductor
Implementation Method 2
the conductors are arranged to permit free air cooling of the cable on at least two sides of each conductor
Implementation Method 3
Alternating currents of the same phase and frequency in adjacent insulated conductors arranged in a bundle also have an electromagnetic effect on each other. This effect, referred to as the 'proximity effect'
Data Source
AI summary
A multi-phase cable, the cable including a plurality of conductors for conducting currents of two or more different phases, each phase being associated with one or more conductors and each conductor being associated with one respective phase. Each conductor has a cross-section with at least one dimension that is sized to decrease a skin effect of the conductor at a maximum or nominal operation frequency of the conductor. The conductors are arranged to permit free air cooling of the cable on at least two sides of each conductor, and such that each conductor of a given phase has, as immediate neighbors, only conductors of one or more different phases.