World’s 1st Large Flexible Power Autotransformer

Power transformers are one of the most difficult electric transmission network components to replace in emergency situations. If a spare is not available, a new power transformer must be designed and manufactured, a process that can span many months, even if raw materials and components are readily available.

Today, most of them fail due to:

  • Transformer age (more than 33% of the US transformers have more than 50 years of use)
  • Weather events
  • Vandalism, terrorist attack

Prolec GE and GE Research developed a solution specifically for large utilities or groups of utilities where different voltages and impedances may be required when considering the purchase of spares. Instead of being solely dependent on a large pool of highly customized spare units, flexible transformers with multiple low voltage ratings and adjustable impedance capabilities could be a simpler and more cost-effective solution, not only for emergencies, but as permanent replacements.



Adjustable impedance range (online/offline)

Multiple LV voltage ratings

Remote monitoring

Design and tested according to IEEE C57.12.00 and C57.12.90

Full compliance of short-circuit dielectric and thermal IEEE requirements

First prototype development supported by the DoE.