Looking for transformational knowledge
Participating in the applied industrial research project NewLifT – short for New Liquids for Transformers – Nynas’ researchers aspire to build transformational bridges between fundamental knowledge and industrial practice.
Thomas Norrby
Professor
Technical Manager for Electrical Industry, Nynas.
“The NewLifT project focuses on the properties of transformer fluids of fundamentally different nature, encompassing both well-known, established, and novel liquids. Thermal properties affecting cooling behaviour, moisture tolerance, gas bubble formation and low temperature performance will add much-needed fundamental knowledge, which in the end will facilitate the design and selection of better transformer oils,” says Professor Thomas Norrby, Technical Manager Electrical Industry.
The thermal and dielectric properties of insulating liquids are influenced by the fundamental physical and chemical properties of the transformer oil.
These properties are of crucial importance, as they impact the design, manufacture, and maintenance of power transformers. The safe, reliable, and economical performance of transformers is critical for the entire power grid, and a key enabler for satisfying rapidly growing demands for electricity.
“The level of knowledge regarding the thermal properties of insulating fluids varies. Some conventional transformer oils have been studied for many decades, whereas novel and alternative liquids have been intensively researched only in the past 20 years. Meanwhile, new dielectric fluids continue to be introduced to the market, which is why the NewLifT project is so important,” says Thomas Norrby.
Nynas’ NewLifT team: Dr. Elena Minchak, Research manager, Robert Fairholm, Sr. Development Engineer, Professor Thomas Norrby, Technical manager Electrical Industry, and Dr. Pär Wedin, Senior Staff Researcher on one of their visits to SINTEF in Trondheim, Norway.
Funded by the Research Council of Norway (NRC) and industrial partners like Nynas, the knowledge-building New- LifT project is specifically aimed at benefitting the electrical infrastructure industry through investigations of the thermal properties of novel classes of transformer insulating liquids. Their suitability for use under arctic conditions is a special focus for the research project.
“Low-temperature conditions impact both the thermal and the electric performance of different fluids. The nature of the fluid might change, for example it can gel or crystallise as it approaches solidification,” he explains. Therefore, he argues, it is critical to investigate any changes in electric breakdown probability, while assessing the liquid performance at the temperatures experienced in the arctic region.
Emphasising the important role Nynas is playing in the project, Dr. Elena Minchak, Research Manager, adds:
“Nynas NYTRO® transformer oils are renowned for their excellent cooling efficiency and include both well-known and new products. We are very excited and proud to be working with our partners in this important collaborative research initiative, joining forces between research organisations and industrial stakeholders. By expanding the deep knowledge and getting new insights for future product development, we strive to contribute to advancing state-of-the-art research and facilitating new discoveries together with our customers.”
“We are confident that the results will mitigate industryrelated challenges regarding the knowledge and competence needed, and hence provide the solid foundation for future standards related to transformer insulating liquids,” she says.
Rewriting transformer rules
Led by SINTEF, one of Europe’s largest independent research organisations, the NewLifT project gathers under its umbrella partners from the entire value chain, covering manufacturers as well as owners of transformers. At this stage, Nynas is the only liquid producer taking part.
Dr. Pär Wedin and Dr. Camilla Espedal discussing the new experimental thermal rig used in the NewLifT project.
The common aim of the 4-year project, with a budget of over 1.7 million USD, is to provide the electrical industry with scientifically solid, data-based knowledge that may ultimately lead to transformer design rules being rewritten.
Current models for transformer liquids and insulating systems are being scrutinised for validity, and new alternative models tested in various experimental rigs. Advanced computational fluid dynamics (CFD) modelling is being used to verify the relationship between different crucial parameters for heat transfer in transformers (for example, viscosity and cooling properties). This will also enable the researchers to quantify the effect of key factors, paving the way for understanding of even more complex problems.
The project aims to develop liquid-specific models suited for digitalisation and tailored diagnostics for not only heat transfer phenomena and cooling properties, but also for moisture dynamics between the transformer fluid and the paper winding insulation, as well as bubbling phenomena predicting the temperature limits for safe operation.
Offering sustainability
Nynas’ innovative transformer liquid NYTRO BIO 300X is leading the field of new alternative insulating fluids. Being biobased, biodegradable, renewable, and recyclable, it offers a range of sustainable opportunities. In addition, its ultra-low viscosity enables superior heat transfer capabilities that promise to improve the performance of transformers, extending their life and uprating the power output. The benefits of NYTRO BIO 300X are currently being confirmed in many field trials and in applications across Nynas’ markets, such as in Gothenburg in Sweden, where the local utility company is running a field trial using NYTRO BIO 300X liquid in one of three identical 40 MVA transformers.
