Phase-Interweave Power Cable Layout for Skin and Proximity Effects
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Solution Overview
Problem
Traditional Litz constructions face issues with insulated strands shorting over time and unreliable termination methods, and they do not effectively maximize power carrying capability due to small gauge sizes and increased strand counts, which lead to skin and proximity effects.
Innovation Solution
A power cable design with individual conductors optimized for 100% cross-sectional usage, featuring a phase interweave configuration, an external shield, and a central ground conductor to cancel proximity effects, allowing for robust construction and conventional termination techniques like soldering or crimping.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If traditional Litz construction with small gauge strands and high strand count is used, then skin effect is reduced, but the insulated strands short together over time and termination becomes unreliable
Solution Approach 1:
The cable is divided into multiple individually insulated conductors rather than using traditional Litz wire construction. Each conductor is insulated separately and positioned in specific locations within the cable cross-section, allowing for reliable termination while maintaining skin effect reduction through proper geometric distribution.
Solution Approach 2:
The patent transitions from the traditional Litz wire approach (many fine strands twisted together) to a spatial arrangement of individual conductors positioned at specific radial distances and angular positions from the cable center. This dimensional reorganization allows each conductor to be terminated reliably while maintaining the skin effect cancellation benefit.
2Loss of energy
If traditional Litz construction with small gauge strands is used, then skin effect is minimized, but power carrying capability is reduced due to small cross-sectional area
Solution Approach 1:
Different conductors are positioned at different radial distances from the cable center, with each position optimized for its specific function. Conductors closer to the center carry different currents than those at the periphery, allowing each conductor to operate at optimal current density while collectively providing high power capacity and skin effect cancellation.
Solution Approach 2:
The cable uses a composite construction combining multiple conductors of different sizes and materials (copper, copper-clad aluminum, aluminum) positioned in specific configurations. This allows optimization of each conductor's contribution to power carrying while maintaining overall skin effect reduction through the geometric arrangement.
3Power
If conductors are arranged to maximize power carrying capability, then cross-sectional usage is optimized, but proximity effect increases
Solution Approach 1:
The conductors are arranged in a specific geometric pattern with alternating phases positioned at calculated angular intervals. This preliminary arrangement creates opposing magnetic fields that cancel each other, preventing proximity effect from developing even when conductors are positioned to maximize power carrying capability.
Solution Approach 2:
The patent positions conductors of the same phase at equidistant locations from the cable center, creating equipotential surfaces for each phase. This symmetrical arrangement ensures that magnetic fields from conductors of the same phase reinforce each other constructively, while fields from opposite phases cancel, eliminating proximity effect 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
The design maximizes power carrying capability, reduces skin and proximity effects, and enables reliable termination, resulting in a more robust and efficient power cable with minimized effective resistance.
Implementation Method 1
The diameter of the individual conductors is proximate to, but below, the skin effect cutoff diameter of the individual conductors
Implementation Method 2
The power cable reduces the skin effect of the power cable and the proximity effect of the power cable
Data Source
AI summary
A power cable having a central ground conductor. Phase interweave power conductors are positioned about the central ground conductor. Individual phase interweave power conductors have the same diameter. The individual phase interweave power conductors have a cross sectional area which is optimized. Each of the individual phase interweave power conductors is configured to support 100% cross sectional usage to maximize power carrying capability. The power cable reduces the skin effect of the power cable and the proximity effect of the power cable.