JST Transformateurs (formerly Jeumont Schneider Transformateurs), a leading supplier of power transformers, has become the first one to design the world's largest three-unit shell type single phase Generator Step-Up transformer or GSU. Following the final set of successful testings at the transformer's factory in Lyon, the company delivered the GSU (650 MVA per phase, 1950 MVA total) to EPR Flamanville site of EDF (Electricit? de France) in March 2011. JST Transformateurs will unveil this technology at the India Nuclear Energy Trade show being held from 28th September to 1st October 2011 in Mumbai.

The transformer will be used in the Flamanville EPR (European Pressurized Reactor or Evolutionary Power Reactor) in France, one of the two upcoming EPR nuclear plants with the highest rated capacity in the world. JST Transformateurs has designed the 3 single-phase 650 MVA 400 kV GSUs and the 3 auxiliary supply units (100 MVA 400 kV) for this power generation plant. Starting in 2014, the Flamanville EPR plant made by EDF will generate 1600 megawatts (MWe) of power.

Leader in nuclear power technology, JST Transformateurs has opened a new dimension to the shell type technology, with the construction of these poles. The 1950 MVA transformer will be the first shell type GSU in the world to convert electricity for a single 1600 MWe plant. As a major component of generation system, the Generator Step Up transformers must convert the 23 kV voltage of the generator to the 400 kV grid voltage. "With this transformer, we have taken over the role of technology leader in this industry. The innovations introduced here will benefit the entire product range," said Eric Lajus, CEO of JST Transformateurs company.

Based on a vast experience in the construction of power transformers, JST Transformateurs uses the latest innovative solutions to design these units. Thanks to the essential technological expertise, which enables us to double the life of these transformers to 60 years at full power. The research and development work focuses primarily on meeting the exceptionally high standard demands for the insulation and cooling systems of these highly reliable, long-life transformers, while cutting down losses.

In compliance with a contract executed jointly with Siemens T&D France, JST Transformateurs has also delivered four 100 MVA extra-high voltage, turn-key SUT transformers to the Flamanville EPR nuclear plant.