1. Transformer Corrosion Background

As a core component of the power system, the transformer plays a key role in distributing electrical energy, changing voltage, and transmitting power within the grid. In recent years, several cases of transformer failures caused by oil sulfur corrosion have been reported. Oil sulfur corrosion refers to the corrosion of metals (windings) due to the presence of corrosive sulfur in transformer insulating oil, which leads to a reduction in the insulation performance of the transformer and causes failures. Studies have shown that dibenzyl disulfide (DBDS) is the primary corrosive sulfur that reacts with copper windings in transformer oil.

I. Reference Standards

Current national standards, relevant regulations, and mandatory standard provisions;

"Code for Construction and Acceptance of Building Anti-corrosion Engineering" (GB50212-2002)

"Standard for Corrosion and Rust Removal Levels of Steel Surface Before Coating" (GB8923-1988)

"Safety Regulations for Coating Operations and Safety Management Rules" (GB6514-1995)

"Quality Requirements for Anti-corrosion Coatings" (GB6514-1991)

"Safety Regulations for Coating Operations, Paint Process Safety, and Ventilation Purification" (DJ/T6931-1999)

"Code for Construction and Acceptance of Industrial Equipment and Pipeline Anti-corrosion Engineering" (HGJ229-91)

"Safety Regulations for Coating Operations and Safety of Surface Preparation Process" (GB7692-87)

"Noise Limits at Construction Sites" (GB12523-90)

ISO9001 Quality Management System Documents

ISO14001 Environmental Management System Documents

GB/T28001 Occupational Health and Safety Management System Documents

I. Design Basis

Environmental Conditions: The corrosion level of atmospheric environments on steel structures can be determined according to Table 1.

I. Dry-Type Transformer Corrosion Protection Plan

Dry-type transformers are widely used in places such as local lighting, high-rise buildings, airports, docks, CNC machinery equipment, etc. Simply put, a dry-type transformer refers to a transformer where the core and windings are not immersed in insulating oil. The transformer plays a crucial role in the safe and stable operation of power systems.

Dry-type transformers are particularly susceptible to corrosion from rainwater. Continuous rainfall can have a strong corrosive effect on dry-type transformers. Many dry-type transformers, once exposed to water, may experience short circuits, causing them to malfunction or even catch fire. The transformer body is exposed to the atmosphere, and when the relative humidity of the air is high, the insulation absorbs moisture from the air. This causes the transformer to fail to operate properly, which makes corrosion prevention for dry-type transformers a matter of great importance.

Table 1: Corrosion Protection of Dry-Type Transformer Outer Walls Using Graphene Technology

Table 2: Corrosion Protection of Dry-Type Transformer Inner Walls Using Graphene Technology

1. Transformer Corrosion Protection Plan for Offshore Installations

The outer casing of offshore or coastal power transformers is subjected to corrosion of varying degrees due to the long-term exposure to the high temperature and high humidity of the marine environment, as well as the impact of seawater splashing. In a marine environment, the atmosphere contains a large number of chloride ions, which have a high electrical conductivity, easily forming micro-cells and macro-cells on metal surfaces, increasing the activity of corrosion, and damaging the passivation film on the metal surface. The corrosion rate and performance of various materials decrease much faster in a marine environment than in a land-based atmospheric environment.

Table 1: Corrosion Protection for Transformer Inner Wall Using Coating Technology

Table 2: Corrosion Protection for Transformer Outer Wall Using Graphene Coating Technology

1. Transformer Corrosion Protection Plan for Inland Areas

A transformer is a device that transmits electrical energy or signals using the principle of electromagnetic induction. It has the functions of voltage transformation, current transformation, and impedance transformation. In the power system, power transformers increase the voltage generated by the power plant for long-distance transmission and then reduce the voltage at the destination for use, thus reducing energy loss during transmission.

With the rapid development of inland power industries, the atmosphere in power plants contains high levels of harmful gases such as sulfur dioxide (SO₂), nitrogen dioxide (NO₂), chlorine (Cl₂), and ammonia (NH₃), which cause significant corrosion to transformers installed and operated outdoors.

Table 1: Inner Wall Corrosion Protection of Transformers Using Coating Technology

Table 2: Outer Wall Corrosion Protection of Transformers Using Graphene Coating Technology