Tunable is currently working on a collaboration project with Statnett, Hafslund and Statkraft among others, to develop an analyzer for monitoring gas in transformer oil. By monitoring the evolution of gas, it will enable identification of faults at an early stage. The final solution will help the electric power industry improving the reliability as well as optimize investment in high-voltage transformers.

The goal for this project is to increase the reliability of the power supply and give the grid operators an opportunity to utilize the network optimally by reducing the load on transformers that indicate faults and perform preventive maintenance with a significant lower price than today’s gas analyzer.

The security of supply of electricity is important for the power-intensive industry, hospitals, national infrastructure and for the private electricity user. The energy carrier of the future in a greener society, where fossil energy sources are being phased out, is very likely to be electric. Electric cars and other electric transport vehicles are being phased in, and the Norwegians Governments goal is that all new cars will be electric within 10 years. In this context, the transformers will be central to the power transmission to consumer, and such an analyzer will then make an important contribution to greener society.

In Norway, 98% of the electric power are coming from renewable sources, mainly hydropower. Before the electrical power can be used, the power needs to be transported from the power plant and out to the consumer. The power transformer is an important component in this transport. It transforms the voltage between different levels, enabling power transfer over long distance, and finally distribution to the end user. Malfunction or breakdown of a power transformer can be very expensive for the owner (power plant or industry), interrupts the power supply, and can cause large environmental impacts and even loss of life.

Most of the largest power transformers are filled with oil. The oil has two main purposes; it cools the transformer and it improves the isolation between the coils. Monitoring of gases dissolved in the transformer oil makes it possible to identify possible faults on an early stage. Analysis of the composition, concentrations and increase over time of 7-9 different gas types have been used for several of decades to identify faults like heating, sparking and problems with the insolation. Traditionally this has been done by yearly interval checks or by installing complex systems. We are now making this analysis online and available for the entire grid!

This is a major leap forward, as the challenge has been to get reliable online gas measurements, once the analysis is done, faults can be identified at an early stage.

Many of the power transformers in Norway are old and they are expensive to replace. Our target is therefore to develop an online analyzer for monitoring transformer oil utilizing the well-defined gas analytic approach to enable identification of possible faults on an early stage where repair still is possible, to avoid fires and accidents, and to limit downtime. We will develop a compact, robust and maintenance-free gas analyzer with high sensitivity and long lifespan. Our technology is well suited to measure many gases simultaneously, with high accuracy. Advanced micro and nano-technology permits mass production at a lower price than present technology.


transormator gas olje



Project participants: Tunable AS, Statnett, SINTEF, Hafslund, Statkraft, BKK, Agder Energi, Sira- Kvina kraftselskap, NVE og Delta-X Research.

Finance: NFR (EnergiX-project), Statnett, other project partners



Topics: transformer, trafo, condition monitoring