Gas analysis series | Why it’s important to monitor hydrogen in transformers

Hydrogen gas (H₂) analysis plays a crucial role in the maintenance and reliability of electrical transformers. As transformers are responsible for managing power distribution in grids and industrial settings, ensuring their optimal operation is essential. One of the most significant indicators of transformer health is the presence of dissolved gases in the insulating oil, particularly hydrogen. Hydrogen is often the first gas to appear when there is an abnormal condition within a transformer, such as overheating, partial discharges, or arcing. Detecting and analysing hydrogen levels allows engineers to identify potential faults before they escalate into more severe problems, reducing the risk of unplanned outages and costly repairs.

The impact of elevated hydrogen levels

When hydrogen levels in a transformer increase, it can signal the early stages of insulation degradation. Insulating materials, typically composed of cellulose and mineral oil, are crucial for maintaining the transformer's longevity and performance. As these materials break down due to overheating or electrical discharges, hydrogen is released as a by product. Elevated hydrogen levels, therefore, serve as a warning that the transformer is undergoing stress, which could eventually lead to a fault or failure.

Key issues associated with increased hydrogen levels include:

• Overheating: Excessive heat within a transformer can cause thermal degradation of the oil and insulation, leading to a slow buildup of hydrogen.
• Partial Discharge: Electrical discharges within the insulation can generate localized high-energy areas, producing hydrogen as a result of the breakdown of oil or solid insulation.
• Arcing: More severe electrical faults, such as arcing, can cause a rapid release of hydrogen, as the oil and insulation break down rapidly in response to the intense electrical energy.

If left unmonitored, these issues can accelerate transformer degradation, ultimately resulting in costly repairs or complete transformer failure, causing power outages or significant project downtime.

Why Monitoring Hydrogen Levels Is Essential

Continuous monitoring of hydrogen gas levels is critical because it provides real-time insights into the condition of the transformer. Traditional offline testing methods, which involve periodic sampling of transformer oil, can sometimes miss the early stages of fault development. By the time elevated hydrogen levels are detected, significant damage may have already occurred.

Online monitoring, on the other hand, allows for constant surveillance of transformer health. Any sudden rise in hydrogen concentration can be immediately flagged, enabling maintenance teams to take corrective action before a minor issue turns into a major fault. This proactive approach is especially important for transformers operating in mission-critical environments, where unplanned downtime can have severe financial consequences.

Best Practices for Hydrogen Monitoring

To effectively monitor hydrogen levels, it's essential to use specialized dissolved gas analysis (DGA) equipment. DGA systems continuously measure the concentration of various gases, including hydrogen, and provide early warnings of developing faults. Regular analysis of DGA data helps to identify patterns and trends that might indicate future problems.

One of the most advanced tools for transformer health monitoring is Kelvatek’s TOTUS Total Transformer Monitor. The TOTUS system is designed to provide comprehensive, real-time analysis of transformer conditions, including hydrogen gas levels. It uses state-of-the-art sensors to detect even minor changes in gas concentrations, allowing maintenance teams to spot early signs of insulation degradation or electrical faults. TOTUS can help prevent project downtime by identifying problems before they escalate, enabling timely maintenance and reducing the financial impact of transformer failure.

In conclusion, hydrogen gas analysis is an essential component of transformer maintenance. By monitoring hydrogen levels in real time, operators can detect early signs of insulation breakdown, overheating, or electrical discharges. Online monitoring systems like Kelvatek’s TOTUS provide a reliable way to track transformer health, reducing the risk of unexpected failures and helping to extend the lifespan of these critical assets. This proactive approach ensures that transformers continue to operate efficiently, minimizing downtime and maintenance costs.