Non-linear Dielectric Transformer Insulation

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Solution Overview

Problem

Existing insulation systems for electrical machines, such as transformers, fail to effectively manage varying electrical stresses and thermal cycles, leading to premature degradation and reduced operational life due to constant dielectric properties that do not adapt to changing conditions.

Innovation Solution

A non-linear dielectric insulation system using a composite of glass cloth, epoxy binder, and ceramic fillers, such as lead zirconate titanate, that increases dielectric constant with voltage, providing adaptive electrical protection by smoothing electrical stress and reducing local electric field intensity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional insulation materials with constant dielectric constant are used, then the insulation system provides basic electrical protection, but it fails to adapt to varying electrical stresses and thermal cycles, leading to premature degradation

Engineering Contradiction:
Improveinsulation durabilityVSAvoiddielectric adaptability
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent applies parameter changes by utilizing a dielectric material whose dielectric constant varies with temperature and electrical stress conditions. The material transitions from a constant dielectric state to a variable dielectric state, allowing the insulation system to adapt its electrical properties dynamically in response to changing operational conditions, thereby improving reliability without sacrificing adaptability

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs composite materials by combining a polymer matrix with ceramic particles (such as barium titanate, lead zirconate titanate, or other high dielectric constant materials). This composite structure enables the insulation material to exhibit both the mechanical properties of the polymer and the temperature-dependent dielectric properties of the ceramic particles, achieving both durability and adaptability

Inventive Principle:
Principle #40Composite materials

2Reliability

If insulation materials are designed to withstand extreme electrical rigors, then electrical protection is improved, but the materials deteriorate over long periods under operating temperatures and environmental conditions, reducing operational life

Engineering Contradiction:
Improveelectrical protectionVSAvoidoperational life
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent applies dynamics by creating an insulation system that dynamically adjusts its dielectric constant in real-time based on operating conditions. Rather than relying on static, over-engineered materials, the system actively responds to temperature and stress variations, distributing electrical stress more evenly throughout the insulation and reducing hot spots that would otherwise accelerate degradation and extend operational life

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent utilizes parameter changes in the dielectric constant as a function of temperature and electrical field strength. This dynamic parameter adjustment allows the insulation to provide enhanced electrical protection during high-stress conditions while maintaining flexibility and resistance to degradation under normal operating conditions, thereby extending operational life

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If uniform dielectric strength materials are used, then manufacturing is simplified, but electrical stress is not uniformly distributed, leading to localized breakdown and premature failure

Engineering Contradiction:
Improveinsulation applicationVSAvoidelectrical stress distribution
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent applies local quality by creating regions of different dielectric constant within the insulation material. The ceramic particles are distributed throughout the polymer matrix to create local zones of high dielectric constant that correspond to areas of high electrical stress. This non-uniform local property distribution optimizes electrical stress distribution while maintaining a relatively simple composite manufacturing process

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent uses composite materials to achieve both ease of manufacture and improved electrical stress distribution. The composite structure of polymer matrix with dispersed ceramic particles can be manufactured using conventional insulation application techniques, while the varying dielectric properties of the composite provide automatic electrical stress equalization without requiring complex processing

Inventive Principle:
Principle #40Composite 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 non-linear dielectric insulation system enhances the durability and longevity of electrical machines by uniformly distributing electrical fields, suppressing voltage ripples, and preventing damage from high electrical stresses, thereby extending the operational life without increasing the transformer's size.

Implementation Method 1

an insulating layer having a dielectric constant that varies as a function of voltage or electric field disposed around at least a portion of a winding

Methodology Applied
Scientific EffectNon-linear dielectric property: Dielectric Permittivity

Data Source

PatentEP1933332B1Insulation system and method for a transformer
Publication Date: 2012.02.15 GENERAL ELECTRIC CO
  • EP1933332B1 patent drawingFigure 1
  • EP1933332B1 patent drawingFigure 2
  • EP1933332B1 patent drawingFigure 3

AI summary

A transformer (10) including a magnetic core (14) is provided. The magnetic core (14) includes multiple laminate stacks having at least one opening. The transformer (10) also includes a winding (30) comprising a conductive material around the magnetic core (14) through the at least one opening (20) and surrounded by an insulating layer (54) having a dielectric constant that varies as a function of voltage.