The beauty of transformers

Hyosung, the Korean maker of power transformers, finds naphthenics to be the key to stability, reliability and the global market.

Case story


  • COMPANY Hyosung
  • PRODUCT Nynas naphthenic oil
  • SEGMENT Transformer oils

Hyosung Changwon Plant

The Hyosung Changwon Plant, opened in 1977, is arguably one of the largest power transformer plants in the world, boasting 100,000 MVA production capacity and producing customised power transformers on demand. There are more than 1,200 people working in the power transformer division. Hyosung’s domestic market share is 50 percent.

Hyosung, the Korean maker of power transformers, finds naphthenics to be the key to stability, reliability and the global market.

”Speed is a competitive advantage these days,” says Boung Ju Park, General Manager at Hyosung, South Korea. “With Nynas’ expertise in naphthenic oil and its reliable supply chain, the whole supply process is easy and streamlined.”

The partnership between Hyosung and Nynas began when transformer producer Hyosung started expanding into the international market 15 years ago.

“Nynas naphthenic oil is recognised around the world, which makes Nynas a suitable partner for us as we are supplying our transformers globally,” Park says.

Nynas naphthenic transformer oils incorporate anti-oxidation properties. It is possible to procure a large volume of both inhibited and uninhibited types of insulation oil on demand.

Unlike naphthenic oil, paraffin oil is wax-based, and in extreme weather conditions wax can crystallise, leading to performance decline.

This is one reason why the majority of  transformer producers prefer naphthenic oil. Hyosung is aware of the benefits of naphthenics.

Hyosung’s Changwon Plant specialises in power transformers used in conversions from power plants to substations. Electric energy is generated in power plants and distributed through substations to end users, including households and industrial plants. While the power plants generate electricity in large volumes, the end users consume it in smaller amounts.

Thus, transforming voltage and current in between is necessary, and power transformers of varying size are used for effective deliveries and minimized losses.

Hyosung’s transformers are colossal, reaching over three metres high. Naphthenic transformer oils from Nynas play a key role in keeping the imposing devices insulated and cooled down, providing the stability and safety that are crucial to the success of the operations.

Park says power transformers are the most beautiful and efficient creations he knows. He joined Hyosung in 1992 after graduating from Hanyang University, one of the top engineering schools in South Korea

“Life was simpler back then, but we studied hard,” Park says with a laugh. His educational decision would turn into a 24-year career solely devoted to developing and designing power transformers.

Fifteen years ago, Hyosung’s domestic sales ac-counted for 70 percent of the total, and its presence in the global market was just taking shape. Nynas has been an important partner in Hyosung’s export amibition, that now accounts for 80 percent of its sales, with clients in more than 70 countries.

Park is proud of his work and of the fact that transformers boast 99.7 percent energy efficiency. “I remember the surge of pride in my chest when I saw the first power transformer that I designed come to life,” Park says.

All Transformer oils

Nynas has the world's widest range of transformer oils – developed to handle just about every conceivable climate, design and operating condition.

See a selection of our transformer oils based on their key characteristics, including viscosity. For more information on each product, simply download the relevant Product and Safety Data Sheets. See all products