Insulation Support Strip with Circumferential Slots

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Solution Overview

Problem

High-voltage oil-filled transformers face insufficiency in insulation capacity, leading to increased distances between lead-out components and transformer tank walls, risking breakdowns and reduced power density due to inadequate support rail insulation.

Innovation Solution

An insulation support strip with milled circumferential slots on a rectangular or circular beam-like module made of pressboard, enhancing insulation capacity and flexibility, and featuring adjustable slot density and U-shaped insulation plates for improved creepage path lengthening and mechanical connection options.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If support rails made of plastic are used to provide mechanical stability, then ease of operation is improved, but insulation capacity deteriorates leading to increased breakdown risk

Engineering Contradiction:
Improvemechanical stabilityVSAvoidinsulation capacity
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The support strip combines pressboard (providing mechanical strength and stability) with milled circumferential slots (providing enhanced insulation capacity). This composite structure integrates the advantages of both materials: the pressboard base offers mechanical stability while the slot configuration dramatically improves insulation performance by lengthening the creepage path.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The invention changes the geometric parameters of the support strip by introducing circumferential slots with specific dimensions (depth of 20mm, width of 10mm, spacing of 4-15cm). These parameter changes transform the surface geometry to increase the creepage path length, thereby improving insulation capacity without compromising mechanical stability.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If distances between lead-out components and tank walls are increased to prevent breakdowns, then reliability is improved, but transformer volume increases reducing power density

Engineering Contradiction:
Improvebreakdown preventionVSAvoidpower density
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The invention changes the insulation mechanism by transforming the support strip surface geometry through circumferential slots. This parameter change in surface configuration allows the same physical distance to provide higher insulation capacity, enabling reduced spacing between components while maintaining reliability, thus improving power density.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The circumferential slots create local quality variations on the support strip surface, concentrating insulation enhancement at critical areas where creepage occurs. This localized improvement in insulation quality allows for more compact overall design without compromising breakdown prevention.

Inventive Principle:
Principle #3Local quality

3Reliability

If slot density is increased in critical areas to improve insulation, then insulation capacity is improved, but manufacturing complexity increases

Engineering Contradiction:
Improveinsulation capacityVSAvoidslot configuration
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention applies different slot densities to different areas of the support strip based on local insulation requirements. Critical areas receive higher slot density (4cm spacing) while less critical areas have lower density (8-15cm spacing). This localized differentiation optimizes insulation capacity where needed while controlling overall manufacturing complexity.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP2490230B1Insulation support strip
Publication Date: 2014.06.25 ABB TECHNOLOGY AG
  • EP2490230B1 patent drawingFigure 1
  • EP2490230B1 patent drawingFigure 2~3
  • EP2490230B1 patent drawingFigure 4

AI summary

The strip (10) has a beam-like base module (12) including a rectangular cross-section made from a solid insulation material, and a groove (22) and a borehole (24) provided at two ends (14, 16) of the strip. Slots (18) circumferential at outer sides of the base module in a plane are provided in sections transverse to a longitudinal extension of the base module. An area including a connection part (20) for supporting components is provided in the base module. A U-shaped insulating plate is fitted in one of the slots in a form-fit manner. Independent claims are also included for the following: (1) an insulation support scaffold (2) an oil transformer.