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Assessing transformer condition

29 November 2017

Vaisala is working with a range of power utilities, maintenance providers and asset owners to bring the first commercial units of its Optimus DGA Monitor for Transformers online.

In recent months, Vaisala has delivered Optimus units to various customers in Europe, the Middle East and Africa, the Americas and Asia. Vaisala looks to keep pace with demand and an expected increase in production in 2018.

As transformer fleets continue to age, the likelihood of faults and failure increases accordingly. Real-time condition monitoring enables asset owners to identify and address potential issues before they result in costly failure, reducing maintenance costs and boosting production and performance.

While various DGA methods are widely used in the international power generation and transmission sector, the Optimus DGA Monitor offers a number of practical, time- and cost-saving benefits that Vaisala believes will dramatically improve transformer maintenance and minimise power plant disruption.

Vaisala's Optimus monitors transformer oil for the presence of moisture and seven different gases. By tracking real-time levels of hydrogen, carbon monoxide, carbon dioxide, methane, ethane, ethylene and acetylene, it gives asset owners a comprehensive understanding of the condition and health of a transformer, enabling them to make informed proactive maintenance decisions.

While many DGA systems available in the market source equipment and sensors from different manufacturers, the infrared sensor technology used in the Optimus has been developed in-house by Vaisala. This integrated approach, using only Vaisala-manufactured sensors and equipment, is said to ensure optimal performance regardless of operational conditions.

In addition, the Optimus DGA Monitor's installation process is simple, and the unit is designed and delivered to enable asset owners to install and bring the device online independently and in less than 2h. Once installed the device delivers reliable results in real-time through a browser-based user interface.

Optimus uses vacuum gas extraction and hermetically sealed and protected optics to completely eliminate the false alarms of the kind that frequently afflict on-site DGA systems. Optimus ensures high quality gas selectivity through its use of vacuum gas extraction, which operates regardless of oil temperature or gas pressure, and by employing spectral scanning to aid selectivity.

The robust and durable device has components and piping that are made of stainless steel and aluminum, a magnetic gear pump and valves, and relies on no consumables that would require servicing or replacing. With a practical browser-based user interface, the device has no need for additional software.

"DGA analysis has long been accepted as one of the most effective means of assessing transformer condition," said Teemu Hanninen, product manager at Vaisala. "At Vaisala, we recognised that there was room to improve the reliability, usability and lifetime costs of the existing devices, and we decided to take on the challenge. With its proven durability and sensors protected from contamination, Optimus has shown that it can deliver reliable and accurate data."

Commenting on site visits Vaisala has carried out around the world, Hanninen added: "We have received a lot of positive feedback from those customers who have already received and installed their units – and we're anticipating strong demand for Optimus in 2018. 

There will be an opportunity to learn more about Vaisala's power offering at the Low Carbon Networks & Innovation Conference in Telford on 6th and 7th December.