Hitachi Energy has successfully tested a 765kV/400kV single-phase, 250 MVA natural ester-filled oil transformer.
This breakthrough innovation makes this transformer the first in the world at this voltage and power level, with the implementation of ester oil providing a biodegradable and safety-by-design option for operators of ultra-high-voltage AC grids.
The transformer was designed, manufactured and tested to further develop Hitachi Energy’s TrafoStar transformer technology platform, which is available in all power transformer factories worldwide.
Natural ester oil
Transformers have traditionally used mineral oil, well known for its excellent electrical properties, as an insulation and cooling medium. More recently, transformer technology innovation has advanced the use of alternative fluids, such as natural ester, with additional safety and environmental performance features.
The tested 765 kV transformer uses natural ester fluid with a flash point twice as high as mineral oil and with self-extinguishing properties. Combined, these qualities make it safer than mineral oil transformers. Additionally, virgin natural esters are up to 100 percent biodegradable within 28 days, reducing the risk of environmental pollution resulting from insulating fluid leakages. Safety is further enhanced by Hitachi Energy’s rupture-resistant TXpandTM technology.
Sustainable and secure power system
“Driven by the accelerating global energy transition and the continuous growth of electricity demand, the supply of new and innovative transformers is more important than ever. High-voltage, natural ester-filled transformers provide grid operators with an efficient and safe solution, especially for environmentally sensitive areas. We are working closely with customers and partners both to upgrade existing ultra-high-voltage power grid infrastructure and develop new energy projects that help to create a more sustainable and secure power system. This development is hugely exciting, and we expect it to meet the needs of a growing number of customers worldwide,” said Bruno Melles, Managing Director for the Business Unit Transformers, Hitachi Energy
TrafoStar technology
Hitachi Energy has been supplying natural ester-filled transformers for over 20 years, with products installed in over 40 countries. The company’s TrafoStar transformer technology platform harmonizes transformer design, manufacturing processes and quality control measures across all Hitachi Energy power transformer factories worldwide, ensuring consistency and excellence in every transformer produced.
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