Guard Wire Shielding for Aircraft Power Feeder Reliability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Aircraft electrical systems using composite materials are vulnerable to electromagnetic effects like lightning strikes due to reduced conductivity, necessitating improved shielding in power feeder systems that also minimize weight and heat buildup.
Innovation Solution
A shielded power feeder system comprising unshielded power feeder conductors and grounded guard wire conductors forming a bundle, with the guard wires positioned adjacent to the power conductors and only the neutral conductor surrounded by a conductive shield to direct electromagnetic interference to ground, creating a magnetic field that opposes induced currents in the power conductors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a grounded metallic sheath envelops the entire cable bundle, then electromagnetic interference protection is improved, but weight increases
Solution Approach 1:
The patent divides the shielding function into two parts: (1) a grounded metallic sheath that envelops only the neutral conductor, and (2) individual insulated guard wire conductors positioned adjacent to each power conductor. This segmentation allows the system to achieve electromagnetic interference protection without requiring a continuous metallic sheath around the entire bundle, thereby reducing weight while maintaining protection effectiveness.
Solution Approach 2:
The patent applies shielding locally rather than uniformly throughout the entire cable bundle. The grounded metallic sheath is applied only to the neutral conductor where it is most needed for lightning protection, while power conductors are protected by individual guard wires. This local quality approach reduces the overall amount of metallic shielding material required, thus reducing weight while maintaining adequate protection.
2Reliability
If a grounded metallic sheath envelops the entire cable bundle, then electromagnetic interference protection is improved, but heat build-up increases
Solution Approach 1:
By segmenting the shielding arrangement so that the grounded metallic sheath envelops only the neutral conductor rather than the entire bundle, the patent creates gaps between conductors that allow heat dissipation. The individual guard wires provide protection without creating a continuous enclosed space that would trap heat around all conductors.
Solution Approach 2:
The patent applies the grounded metallic sheath locally only to the neutral conductor rather than uniformly to the entire bundle. This local application reduces the total volume of metallic enclosure, thereby reducing the heat-trapping effect and allowing better thermal management of the power conductors.
3Weight of moving object
If composite materials are used for aircraft skin, then weight is reduced, but electromagnetic interference protection deteriorates
Solution Approach 1:
The patent introduces individual insulated guard wire conductors as intermediary protective elements between the power conductors and the electromagnetic interference environment. These guard wires, positioned adjacent to each power conductor and connected to ground, act as mediators that divert electromagnetic interference away from the power conductors, compensating for the loss of protection provided by composite aircraft skin.
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 design provides effective protection against electromagnetic interference-induced damage while reducing overall weight and heat buildup by using a minimal shielding approach that directs electromagnetic interference to ground, enhancing the reliability of electrical systems in aircraft.
Implementation Method 1
the at least one power feeder conductor and the at least one grounded guard wire forming a bundle
Implementation Method 2
creating a magnetic field that opposes induced currents in the power conductors
Implementation Method 3
protection against electromagnetic interference-induced damage
Data Source
AI summary
A shielded power feeder system may include at least one unshielded power feeder conductor, and at least one grounded guard wire conductor positioned adjacent to the at least one unshielded power feeder conductor, the at least one unshielded power feeder conductor and the at least one grounded guard wire forming a bundle.