Transformer Core Coating System for Corrosion Resistance

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Solution Overview

Problem

Dry-type transformer cores are susceptible to corrosion in harsh environments due to exposure to pollutants, moisture, and high temperatures, leading to degradation and delamination of protective coatings.

Innovation Solution

A three-layer corrosion-resistant coating system comprising a zinc silicate primer, a polysiloxane composition, and a room temperature vulcanizing silicone rubber layer is applied to the transformer core, providing a durable barrier against environmental factors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a protective coating is applied to the transformer core, then corrosion resistance is improved, but the coating degrades and delaminates under harsh environmental conditions

Engineering Contradiction:
Improvecorrosion resistanceVSAvoidcoating service life
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The coating system is divided into three distinct layers: an etch primer layer for adhesion, a intermediate coating layer for corrosion inhibition, and a topcoat layer for environmental protection. This segmentation allows each layer to specialize in specific functions, improving overall durability and preventing delamination

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent uses a composite coating system combining organic and inorganic materials - the etch primer contains zinc silicate and aluminum phosphate for chemical bonding, the intermediate layer uses epoxy for adhesion, and the topcoat uses polysiloxane for weather resistance. This composite structure provides synergistic protection against corrosion and environmental degradation

Inventive Principle:
Principle #40Composite materials

2Adaptability or versatility

If the core is exposed to harsh environments, then the transformer operates in real-world conditions, but corrosion and degradation occur

Engineering Contradiction:
Improveenvironmental adaptabilityVSAvoidcorrosion damage
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The etch primer layer is applied first to create a chemically bonded surface that prevents corrosion before it can affect the core. The zinc silicate and aluminum phosphate in the primer react with the ferromagnetic surface to form a corrosion-resistant base, anticipating and preventing environmental damage

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The polysiloxane topcoat creates a hydrophobic, chemically inert barrier that protects the core from moisture, UV radiation, and pollutants. This inert outer layer prevents harmful environmental factors from reaching the ferromagnetic core, allowing operation in harsh conditions without degradation

Inventive Principle:
Principle #39Inert atmosphere (Inert environment)

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 coating system significantly reduces corrosion, as demonstrated by minimal damage after 1,000 hours of salt fog testing, maintaining the integrity of the ferromagnetic core in harsh conditions.

Implementation Method 1

a zinc silicate primer

Methodology Applied
Scientific EffectGalvanic inhibition:

Implementation Method 2

a polysiloxane composition

Methodology Applied
Scientific EffectBarrier formation:

Implementation Method 3

a room temperature vulcanizing silicone rubber layer

Methodology Applied
Scientific EffectVulcanization:

Data Source

PatentEP2795640B1Corrosion-resistant coating system for a dry-type transformer core
Publication Date: 2020.04.29 ABB POWER GRIDS SWITZERLAND AG
  • EP2795640B1 patent drawingFigure 1
  • EP2795640B1 patent drawingFigure 2
  • EP2795640B1 patent drawingFigure 3

AI summary

A protective coating system for application to exposed surfaces of a transformer core prevents corrosion of the core. The protective coating is suitable for use in industrial and marine environments where many factors impact the life of the transformer core. The protective coating comprises at least three coating layers. The first coating layer is an inorganic zinc silicate primer. The second coating layer is a polysiloxane. The third coating layer is a room temperature or high temperature vulcanizing silicone rubber. A silicone rubber sealant may be further applied to outer edge surfaces of the core.