Energy supply: What does a transformer failure mean in operation?

Transformers play an important role in regulating the voltage in power circuits. When they fail, entire systems can stop working and cause business interruptions that are costly and even dangerous. In this article, we look at possible causes of transformer failures, examine the consequences these failures can have for businesses and energy companies and make suggestions for prevention.

Whether owners and operators of individual modules or entire solar and wind farms, whether larger companies that also earn money by feeding electricity into the grid or small businesses - they all have to reckon with a loss of production in the event of a transformer failure. There is a risk of high downtime costs and possibly long lead times for replacing a transformer.

Main causes of a transformer failure in the company

The failure of a transformer can have several causes, such as:

• Overheating: A common cause is overheating, which is usually due to exceeding the maximum load capacity or insufficient cooling. This can accelerate the degradation of the insulation and lead to overloading of all installed materials. 
• Moisture: Another problem is the penetration of moisture, which inhibits the dielectric strength of the insulation. 
• Handling: Physical shocks or improper handling can lead to deformation of the windings and can cause short circuits. 
• Imbalance: In addition, extreme voltage peaks in electrical networks can place excessive stress on transformers, which can lead to insulation and winding failures. 
• Wear and tear: Loose connections and ageing infrastructure also pose an inherent risk, as wear and tear affect the reliability of transformers over time. 

Even the smallest errors in transformer handling should not be ignored. They are often indicators of deeper problems and can herald significant failures. Understanding these causes plays a crucial role in avoiding unplanned transformer downtime.

How can transformer malfunctions be recognised at an early stage and a transformer failure prevented?

Transformer oil is used to insulate the windings, cool the system, transfer heat and isolate the transformer from its environment. The condition of the insulating oil in the transformer reveals a lot about the condition of the transformer. Companies are therefore well advised to have an insulating oil analysis carried out in addition to a regular visual inspection of the transformer and an electrical measurement.

Read more about the properties of insulating oils in this blog article:

• Transformer oil cools, lubricates - what else? Properties of insulating oils

Consequences: This is what a transformer failure means

Sudden transformer failures are not limited to damage to the transformers themselves. They can lead to massive power outages and disrupt work processes or even bring the entire production operation to a stop. The consequences can have far-reaching financial consequences.

Critical infrastructures can also be affected. In addition, the failure of transformers in a power grid can lead to voltage fluctuations that affect other electrical devices and systems connected to the grid.

Read more about the management of insulating oils in this blog article:

• Transformer management: insulating oil is the key 

Ensure lower costs and greater safety with transformer maintenance services

If the transformer oil is not regularly maintained, the transformer's performance becomes inefficient and a lot of energy is lost if the insulating oil is of poor quality. Ensuring the purity and integrity of the transformer oil is therefore an important aspect of comprehensive maintenance services.

This includes regular insulating oil analyses that detect contamination and degradation processes that can lead to performance problems or failures. Proper transformer maintenance goes beyond assessing the condition of the insulating oil and includes inspecting bushings, on-load tap-changers and seals for signs of wear.

Early detection: Tackle potential transformer problems in a scheduled and preventative approach

Comprehensive transformer oil management is better than individual insulating oil analyses or individual maintenance work.

Transformer oil management consists of a combination of

1. consistent maintenance schedules and services, 
2. advanced diagnostic tools and techniques, and 
3. a database that combines historical and current analyses. 

This overall approach to prevention supports duty of care and an uninterrupted power supply, maintains the robustness of the power grid and also extends the lifetime of transformers.

Read more about preventive measures in connection with transformers in this blog article:

• Cost check oil change: when does the insulating oil in transformers need to be replaced?

Conclusion

Transformer failures lead to immediate financial losses due to reduced power generation and supply and can cause entire production stoppages in manufacturing plants. They also result in costs for repairing and replacing the damaged equipment. In some cases, companies have to expect long lead times for the replacement of a transformer. To minimise these risks and potential economic impacts, it is not only recommended to invest in high-quality transformers, but also to proactively and intelligently monitor the transformers. This management can continuously assess the condition of transformers so that performance remains constant and reliable and possible transformer failures can be avoided.

What's more?
The right transformer oil management extends the service life and performance of transformers. How does this work? Read more here:

• How companies can extend the service life of transformers