Microcapsule Electrical Insulation Against Electrical Treeing

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional epoxy composite materials are susceptible to rapid self-curing and fail to effectively mitigate electrical treeing, leading to inadequate resistance against defects in electrical insulation.

Innovation Solution

Incorporating microcapsules with a solid shell containing an electrically insulating liquid into the insulation material, which rupture upon electrical tree formation to release the liquid into treeing channels, thereby impeding further degradation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional epoxy composite materials are used, then the electrical insulation provides basic insulating properties, but it is susceptible to rapid self-curing and fails to effectively mitigate electrical treeing

Engineering Contradiction:
Improveresistance to electrical treeingVSAvoidmaterial composition complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent incorporates microcapsules containing curing agents or repair materials in advance within the electrical insulation material. When electrical treeing occurs, these pre-positioned capsules rupture and release their contents to seal the defects. This preliminary action allows the material to respond automatically to damage without requiring external intervention, thereby improving reliability against electrical treeing while maintaining relatively simple material composition.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent modifies the material parameters by incorporating microcapsules with specific size distributions, wall thicknesses, and curing agent concentrations. By adjusting these parameters, the material achieves optimal balance between maintaining basic insulating properties and providing effective self-healing capability against electrical treeing, thus improving reliability without excessive complexity.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If self-healing functionality is introduced using polymer capsules, then the material can repair defects, but it cures too rapidly and cannot flow into channels formed by electrical treeing

Engineering Contradiction:
Improvedefect toleranceVSAvoidcuring speed
Core Design Contradiction:
ReliabilityVSSpeed

Solution Approach 1:

The patent carefully controls the curing speed by adjusting parameters such as capsule wall permeability, curing agent concentration, and activation energy. The capsules are designed to maintain structural integrity during normal operation but rupture or become permeable at specific thresholds, allowing controlled release of curing agents at appropriate speeds to fill treeing channels effectively, thus achieving high defect tolerance without excessive curing speed.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent incorporates capsules containing curing agents or repair materials in advance within the electrical insulation material. When electrical treeing occurs, these pre-positioned capsules rupture and release their contents to seal the defects. This preliminary action allows the material to respond automatically to damage without requiring external intervention, thereby improving reliability against electrical treeing while maintaining relatively simple material composition.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Reliability

If microcapsules with solid shell containing electrically insulating liquid are incorporated, then the electrical insulation provides enhanced robustness against electrical tree growth, but the device complexity increases

Engineering Contradiction:
Improverobustness against electrical tree growthVSAvoidcapsule integration complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent creates a composite material system by integrating microcapsules containing electrically insulating liquid into the base electrical insulation material. This composite structure combines the properties of the base material with the self-healing capabilities of the capsules, achieving enhanced robustness against electrical tree growth. The composite approach allows maintaining relatively simple overall structure while incorporating advanced functionality through the capsule integration.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent utilizes the porous or cavity-containing structure of microcapsules to embed electrically insulating liquid within the solid shell. This porous material approach allows the capsules to maintain structural integrity while containing the liquid repair material, enabling automatic injection into electrical tree channels when the shell ruptures, thus improving reliability without excessive complexity in capsule integration.

Inventive Principle:
Principle #31Porous materials

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 electrical insulation exhibits enhanced robustness against electrical tree growth, extending the time to breakdown and preventing further damage.

Implementation Method 1

the insulating liquid from the capsule to flow into treeing channels

Methodology Applied
Scientific EffectFluid flow:

Implementation Method 2

the electrical tree eventually hits one of the capsules, punctures it

Methodology Applied
Scientific EffectMechanical rupture: Fracture Mechanics

Data Source

PatentEP3648117B1Electrical insulation, use of an electrical insulation, and method of producing an electrical insulation
Publication Date: 2026.01.14 HITACHI ENERGY LTD
  • EP3648117B1 patent drawingFigure 1~2
  • EP3648117B1 patent drawingFigure 3~5
  • EP3648117B1 patent drawingFigure 6~7

AI summary

An electrical insulation (20) comprises an electrically insulating material (21) and an electrical tree inhibiting material in the electrically insulating material (21). The electrical tree inhibiting material comprising a plurality of capsules (30) having a shell and an electrically insulating liquid within the shell.