Micro-textured Wall Surface for Circuit Breaker Insulation

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Solution Overview

Problem

Low-voltage circuit breakers experience poor post-break insulation due to ablation of materials and condensation of vaporized elements in cold zones, leading to increased conductivity and leakage current, which is challenging to address with existing coatings like paints and oils due to composition control, adhesion issues, and compatibility requirements.

Innovation Solution

A micro-texturing process, preferably laser microtexturing with a femtosecond pulse duration and high peak power, is applied to create a super hydrophobic surface with inhomogeneous residue deposition, forming islands to reduce conductivity by optimizing thermal and mechanical stress resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If coatings like paints, varnishes, or oils are applied to reduce conductivity, then leakage current is reduced, but composition control, adhesion, and compatibility issues arise

Engineering Contradiction:
Improvepost-break insulationVSAvoidcoating application complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The wall material itself provides the insulating function through its inherent properties and geometry, eliminating the need for separate coating materials. The wall is designed to resist recondensation and maintain insulation without requiring external paints, varnishes, or oils.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The invention changes the material parameters of the wall by selecting materials with specific properties (high dielectric strength, low thermal conductivity, appropriate melting point) and optimizing geometric parameters (thickness, surface area, configuration) to achieve the desired insulation performance without coatings.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If conventional coatings are used to reduce conductivity, then insulation is improved, but adhesion on poorly prepared surfaces and compatibility with Rohs and Reach requirements become problematic

Engineering Contradiction:
Improvesurface insulationVSAvoidsurface preparation requirements
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The wall material inherently provides the insulating function without requiring separate coating materials that would need adhesion promotion. The material is selected and prepared in a way that eliminates the need for additional coating layers, thereby removing adhesion concerns entirely.

Inventive Principle:
Principle #25Self-service

3Reliability

If the wall material is optimized for dielectric properties, then insulation is improved, but thermal and mechanical stress resistance deteriorates

Engineering Contradiction:
Improvedielectric insulationVSAvoidthermal and mechanical stress resistance
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The invention employs composite wall structures combining materials with complementary properties. For example, a core material providing dielectric strength is combined with outer layers or reinforcement elements providing thermal and mechanical stress resistance, achieving a balance of all required properties.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

Different regions of the wall are designed with different material properties optimized for their specific functions. The bulk material provides dielectric insulation, while specific regions or layers are optimized for thermal resistance, mechanical strength, or stress distribution, allowing each zone to perform its designated function effectively.

Inventive Principle:
Principle #3Local quality

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 process significantly reduces surface tension, limiting nucleation sites and promoting vertical growth of deposits, resulting in improved post-break insulation and reduced leakage current by creating an inhomogeneous dielectric surface that effectively manages thermal and mechanical stresses.

Implementation Method 1

this process is a laser microtexturing process... this method is a laser microtexturing method whose pulse duration is less than 1 nanosecond and delivering a peak power greater than 10 GW

Methodology Applied
Scientific EffectLaser ablation: Laser Ablation

Implementation Method 2

there is a condensation of the vaporized elements described above in the zones remote from the so-called cut-off zone... promote inhomogeneity in the recondensation of the residues of cleavage by growth of the deposits of these residues on the surface so as to create islands of residues

Methodology Applied
Scientific EffectCondensation: Condensation

Data Source

PatentEP3072142B1Method for treating the surface of a wall in an electrical protection apparatus and apparatus comprising at least one wall treated according to said method
Publication Date: 2018.03.07 SCHNEIDER ELECTRIC IND SAS
  • EP3072142B1 patent drawingFigure 1~1A
  • EP3072142B1 patent drawingFigure 2
  • EP3072142B1 patent drawingFigure 3~4

AI summary

The present invention relates to a method for treating the surface (18) of a wall, with a view to reducing the conductivity thereof, said surface being located in an area referred to as a cold area, said area being located near an area in which an electric arc is likely to occur in an electrical protection apparatus, said cold area constituting an area for recondensing cutting residue. Said method is characterised in that it involves micro-texturizing said surface (18) in order to promote inhomogeneity in the recondensation of cutting residue, by growing deposits of said residue on the surface such as to create islands of residue (19) and thus to restrict the conductivity of the resulting deposit.