Insulating Tube Shatter Protection for Ceramic Insulator Pressure Relief

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Solution Overview

Problem

Existing high voltage apparatuses with ceramic insulators face risks of explosion due to internal failures, leading to porcelain fragments flying at high speed, posing danger to personnel and equipment, and current mitigation solutions like replacing equipment or using composite insulators are not suitable for retrofitting.

Innovation Solution

A shatter protection system comprising concentrically arranged electrically insulating tubes with tailored hole patterns and varying diameters, made of fiber composite material, which can be easily installed to catch fragments and release pressure, while ensuring adequate creepage distance and weather protection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a shatter protection system is integrated into the original product design and manufacture, then the safety performance is improved, but the adaptability for retrofitting existing equipment deteriorates

Engineering Contradiction:
Improvesafety performanceVSAvoidretrofitting capability
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The shatter protection system is divided into separate modular components: an insulating tube with holes and a ceramic insulator. This segmentation allows the protection system to be manufactured independently and then assembled onto existing equipment, enabling retrofitting while maintaining safety performance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The shatter protection components are prepared in advance with pre-drilled holes and specific dimensional specifications. This preliminary preparation enables the components to be ready for installation on existing equipment without requiring modification of the original design, thus facilitating retrofitting.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If multiple concentric electrically insulating tubes are used to increase safety, then the fragment arrest capability is improved, but the device complexity increases

Engineering Contradiction:
Improvefragment arrest capabilityVSAvoidstructure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Multiple electrically insulating tubes are arranged concentrically, with each tube nested within the other. This nesting configuration increases fragment arrest capability by creating multiple barriers, while the concentric arrangement maintains relative simplicity in the overall structure and assembly process.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Stress or pressure

If holes are drilled through the insulating tube envelope surface for pressure release, then the pressure relief function is improved, but the electrical insulation performance deteriorates

Engineering Contradiction:
Improvepressure reliefVSAvoidelectrical insulation
Core Design Contradiction:
Stress or pressureVSReliability

Solution Approach 1:

The insulating tube is designed with holes at specific locations and orientations to provide pressure relief in critical areas while maintaining electrical insulation in other areas. The selective placement of holes ensures that pressure can be released without compromising the overall electrical insulation performance of the tube.

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 system effectively arrests ceramic fragments, reduces the risk of personnel injury and equipment damage, allows energized equipment access, and minimizes power outages by providing a cost-effective, lightweight, and easy-to-install solution for existing ceramic insulators.

Implementation Method 1

The holes through the envelope surface will release the pressure from an explosion in the high voltage apparatus

Methodology Applied
Scientific EffectPressure release: Pressure Drop

Implementation Method 2

the electrically insulating tube will catch fragments flying from the ceramic insulator

Methodology Applied
Scientific EffectMechanical containment: Physical Containment

Implementation Method 3

at least one electrically insulating tube, the electrically insulating tube comprising a plurality of holes

Methodology Applied
Scientific EffectElectrical insulation: Dielectric

Data Source

PatentEP3579251B1Shatter protection
Publication Date: 2026.05.06 HITACHI ENERGY LTD
  • EP3579251B1 patent drawingFigure 1~2c
  • EP3579251B1 patent drawingFigure 3a~3c
  • EP3579251B1 patent drawingFigure 4a~4b

AI summary

The present invention relates to a shatter protection (1) for a high voltage apparatus (2) with a ceramic insulator (3). The shatter protection (1) comprises at least one electrically insulating tube (4, 41, 42), the electrically insulating tube comprising a plurality of holes (5) going through an envelope surface of the electrically insulating tube (4, 41, 42). The electrically insulating tube (4, 41, 42) has a diameter such that there is a minimum distance between the electrically insulating tube (4, 41, 42) and the ceramic insulator (3) when the shatter protection (1) and the ceramic insulator (3) are arranged concentrically. It also relates to a method for producing a shatter protection (1) for a high voltage apparatus (2) with a ceramic insulator (3) comprising winding (S1) a first helix shape of the electrically insulating fiber composite material at a first pitch such that there is a first gap between the winding turns, the diameter of the first helix shape is such that there is a minimum distance between the first helix shape and the ceramic insulator (3) when the first electrically insulating tube (4, 41) and the ceramic insulator (3) are arranged concentrically, and winding (S2) a second helix shape of the electrically insulating fiber composite material onto the first helix shape, the winding of the second helix shape is in the opposite direction as the winding of the first helix shape and it is wound at a second pitch, which is different from the first pitch, and such that there is a second gap between the winding turns. Thereby forming a first electrically insulating tube (4, 41) of the at least one electrically insulating tube (4) with holes (51) formed by the first and second gap between the winding turns.