New Online Measurement Device for Transformer Dissolved Gas Analysis

Power transformers are critical in the energy generation and transmission, but also one of the key vulnerabilities. This is because any transformer downtime will lead to substantial financial losses and to energy shortfalls for national grids. Repairs and replacements can take months, greatly increasing associated business interruption costs.

Efficient condition monitoring is one of the only means of proactively mitigating the risk of transformer downtime. Furthermore, real-time monitoring of the dissolved gas content in transformer insulation oil allows a utility to diagnose any emerging faults quickly and reliably, and plan their maintenance activities better.

"Approximately 50 percent of power transformer faults can be detected with the right online monitoring tools, meaning that severe failures can be prevented. But nobody wants monitors that give false alarms or require regular maintenance. So we created a product that does not," says Product Manager Juhani Lehto at Vaisala Controlled Environment.

Thanks to its careful design and the patented technology, the Vaisala (Finland) Optimus DGA Monitor for Transformers does not give false alarms. It carries an IR sensor based on Vaisala core measurement technology and components manufactured in our in-house cleanroom. It uses vacuum gas extraction, which gives a fully representative sample and means no data fluctuation due to oil temperature, pressure, or type. Hermetically sealed and protected optics prevent sensor contamination, and long-term drift is eliminated with a unique autocalibration functionality.

The Vaisala Optimus DGA Monitor is designed to be installed in less than two hours - just by connecting the oil, power and communications. Browser-based user interface brings ease of use, as no additional software is needed. In case of a disturbance such as power outage, self-diagnostics enables automatic recovery.

We have used our 80 years long experience from operating in different environments and climate conditions to build a solid product that withstands harsh conditions. The Optimus has a robust construction with stainless steel pipes and temperature controlled housing, and it is rated IP66. The hermetically sealed structure tolerates vacuum and pressure variation, and its magnetic pump and valves mean superb performance and durability in any environmental conditions. There are also no consumables to service or replace.