Neutral Conductor Shielding for Aircraft Power Feeder Weight Reduction
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Solution Overview
Problem
Electrical conductors in aircraft, particularly those made of composite materials, are vulnerable to electromagnetic effects like lightning strikes due to reduced shielding, leading to potential damage and heat buildup, and existing solutions with metallic sheaths increase weight and risk of heat issues.
Innovation Solution
A shielded power feeder system with unshielded conductors and a grounded conductive shield only around the neutral conductor, which creates a magnetic field to oppose induced currents, reducing the need for extensive shielding and minimizing weight and heat buildup.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a grounded metallic sheath envelops the entire cable bundle, then electromagnetic protection is improved, but weight increases
Solution Approach 1:
The patent divides the shielding function into segments by applying conductive shields only to specific conductors (such as the neutral conductor or individual phase conductors) rather than enveloping the entire cable bundle. This segmentation maintains electromagnetic protection for critical conductors while eliminating the weight penalty of a complete bundle shield.
Solution Approach 2:
The patent applies different shielding qualities to different parts of the cable assembly. Specifically, certain conductors receive conductive shields while others remain unshielded, creating local variations in shielding quality that match the actual electromagnetic vulnerability and current characteristics of each conductor type.
2Reliability
If a grounded metallic sheath envelops the entire cable bundle, then electromagnetic protection is improved, but heat build-up increases
Solution Approach 1:
By segmenting the shielding application to only those conductors that require it, the patent eliminates unnecessary metallic layers around the entire bundle that would trap heat. This allows heat to dissipate more effectively from unshielded conductors and the overall cable assembly.
Solution Approach 2:
The patent extracts the shielding function from the entire cable bundle and applies it only where necessary to specific conductors. This removal of excessive shielding material eliminates the heat-trapping effect that would occur with a complete bundle envelopment.
3Weight of moving object
If composite materials are used for aircraft skin, then weight is reduced, but electromagnetic shielding capability deteriorates
Solution Approach 1:
The patent introduces conductive shields on specific internal conductors as intermediary shielding elements to compensate for the loss of electromagnetic shielding capability in composite aircraft skins. These localized shields act as mediators that provide the necessary protection without requiring the entire aircraft structure to be conductive.
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
Effectively protects against electromagnetic interference and lightning-induced voltage and current while significantly reducing the overall weight and heat buildup in the power feeder system by using a localized conductive shield around the neutral conductor.
Implementation Method 1
a grounded conductive shield extending over the insulation layer
Implementation Method 2
protection of voltage and current spikes from EME, such as a lightning strike or other electromagnetic effect
Data Source
AI summary
A shielded power feeder system may include at least one unshielded power feeder conductor having first and second ends, a neutral conductor positioned adjacent the power feeder conductor, the power feeder conductor and neutral conductor forming a bundle, and the neutral conductor having a grounded conductive shield.