Dielectric-Coated Steel Jib for High-Voltage Cable Arc Isolation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing high-voltage electrical cable support devices face issues such as faulty grounding connections leading to electrical arcs, missing grounding braids, and conductive fixing elements that propagate arcs, causing damage and fires in underground installations, while composite materials are expensive and complex to design.
Innovation Solution
A steel support arm coated with a synthetic dielectric material, such as polyvinyl chloride, and equipped with non-conductive fastening means, including inserts and cradles, to prevent arc propagation and secure cable fixation without deformation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If steel brackets are used for high voltage cable support, then mechanical strength and load-bearing capacity are improved, but the risk of electric arc propagation and fire increases due to conductivity
Solution Approach 1:
A dielectric coating layer is applied as an intermediary between the steel bracket and the high voltage cable. This coating acts as a mediator that provides electrical insulation to prevent arc propagation while allowing the steel bracket to maintain its mechanical strength and load-bearing capacity.
Solution Approach 2:
The bracket system becomes a composite structure combining steel (for mechanical strength) and dielectric coating material (for electrical insulation). This composite approach allows the bracket to simultaneously provide both structural support and electrical protection against arcs.
2Loss of energy
If grounding braids are added to steel brackets, then energy dissipation during short circuits is improved, but reliability decreases due to contact faults and oxidation
Solution Approach 1:
The grounding function is extracted from the bracket system by using non-conductive dielectric-coated brackets. The bracket itself is designed to be electrically isolated, eliminating the need for separate grounding braids that are prone to oxidation and contact faults. Energy dissipation is achieved through the mechanical isolation and protective coating rather than electrical grounding.
3Strength
If fixing screws and metal flanges are used for cable attachment, then mechanical fixation strength is improved, but electric arc propagation risk increases due to conductive elements
Solution Approach 1:
The dielectric coating serves as an intermediary layer between the metal fixation elements (screws, flanges) and the high voltage cable. This coating prevents direct conductive contact, blocking arc propagation paths while allowing the metal elements to provide necessary mechanical fixation strength.
4Object-affected harmful factors
If composite material brackets are used, then electrical insulation and arc prevention are improved, but manufacturing complexity and cost increase
Solution Approach 1:
The solution uses a composite structure of steel bracket plus dielectric coating rather than fully composite material brackets. This approach achieves the electrical insulation and arc prevention benefits of composite materials while maintaining the manufacturing simplicity and cost-effectiveness of steel fabrication, avoiding the complexity of molding and assembling composite components.
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 solution provides effective insulation against electrical arcs, prevents damage to cables, and ensures safe, fire-resistant fixation, reducing the risk of fires in underground installations.
Implementation Method 1
covered over the entirety of its periphery by overmolding by immersion with a layer of a synthetic dielectric material
Implementation Method 2
a ratchet strap, said strap passing through said openings to encircle the high voltage electrical cable or cables, the ratchet taking position under the support arm
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates to a support device in the form of a gantry for high-voltage electrical cables, exceeding 10,000V, comprising a steel support arm (3) welded onto a steel mounting plate (4) and having two parallel vertical wings (3B) extending along the longitudinal edge of a horizontal wall (3A) on which the high-voltage electrical cables are intended to rest, this device being further covered around its entire perimeter by immersion overmolding of a layer (6) of a synthetic dielectric material and comprising means for fixing (11) at least one high-voltage electrical cable, characterized in that said fixing means (11) comprise: • a cradle (12) on the horizontal wall (3A) for receiving the high-voltage electrical cable(s); • at least two oblong openings (10) extending transversely on the horizontal wall (3A), on either side of the cradle (12);• a ratchet strap (11A) (11B), said strap (11A) passing through said openings (10) to encircle the high-voltage electrical cable(s), the ratchet (11B) taking position under the support arm (3), between the vertical wings (3B).