Conductive Hole Coating for Insulating Housing Grounding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In medium and high-voltage switching equipment, the use of screws directly inserted into insulating materials can lead to increased electrical field density due to sharp edges, causing partial discharges and reducing equipment reliability, whereas dowels with conductive surfaces mitigate this but are not always feasible.
Innovation Solution
Applying a conductive layer to the inner surfaces of holes in insulating housings, which are connected to ground potential, to redirect the electrical field and eliminate triple points, thereby preventing partial discharges.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If screws are directly inserted into insulating material, then device complexity is reduced and ease of manufacture is improved, but electrical field density increases causing partial discharges
Solution Approach 1:
A conductive layer is introduced as an intermediary between the insulating material and the screw. This conductive layer serves as a mediator that redirects the electrical field along its surface, preventing field concentration at the screw's sharp edges while still allowing the screw to provide mechanical fixation. The conductive layer thus resolves the contradiction by enabling direct screw insertion without the harmful electrical field effects.
2Reliability
If dowels with conductive surfaces are used, then electrical field density is reduced and partial discharges are prevented, but device complexity increases and ease of manufacture deteriorates
Solution Approach 1:
Instead of using a complete dowel structure with conductive surface, the conductive properties are applied locally only to the inner surface of the hole where the screw is inserted. This localized application of conductive material provides the necessary electrical field redirection exactly where needed (at the triple point region) without requiring the entire dowel structure, thus simplifying manufacture while maintaining reliability.
3Strength
If screws with sharp thread edges are used, then mechanical fixation is achieved, but electrical field density increases at thread edges causing triple points
Solution Approach 1:
The conductive layer acts as an intermediary that intercepts and redirects the electrical field before it can concentrate at the sharp edges of the screw threads. The field follows the conductive layer's surface instead of concentrating at the metal edges, thus maintaining mechanical fixation strength while eliminating the harmful electrical field density increase.
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 solution enhances the dielectric withstand and mechanical fixation of equipment by minimizing electrical field density within the insulating material, ensuring reliable operation by avoiding partial discharges.
Implementation Method 1
the conductive layers extend toward outside the holes, and wherein the conductive layers are conductively connected or connectable to ground potential
Data Source
AI summary
A fixation system in use for medium or high voltage switching poles, insulators, circuit breakers, or general devices includes: an insulating housing provided with holes, in which screws are screwed into, in order to fix the device on a support, or a further housing. Inner surfaces of the holes are covered with a conductive layer or layers covering the inner surfaces at least partly. The conductive layers extend toward outside the holes. The conductive layers are conductively connected or connectable to ground potential.