ABB has successfully tested and delivered three 750-MVA (765/500/13.8 kV), single phase auto-transformers designed and built for the U.S.-based electric utility, Allegheny Energy. The transformers together weigh over 750 tons and each has enough capacity to power 250 electric locomotives. They are unique in their class given the combination of their MVA rating and large size as well as their high, low and tertiary voltage ratings. The transformers will significantly enhance the electricity transmission capacity in the region and facilitate inter-state power flow.

The three transformers have been delivered and are being installed at AEP’s (American Electric Power) Kammer substation, located near Moundsville, West Virginia. A fourth unit, to serve as a replacement transformer, is scheduled for delivery later in the year. Allegheny is upgrading the substation to improve reliability while reducing congestion and unplanned outages, thus benefiting consumers in the Mid-Atlantic Region.

“ABB continues to raise the bar in terms of technology and innovation,” said Tarak Mehta, Head of ABB’s global Transformers business, a part of the company’s Power Products division. “The special design of these transformers will enable large quantities of power to flow at ultrahigh voltage with minimal losses. This will greatly benefit the utility and serve consumers with better power supply”

Designing and manufacturing the insulation and cooling systems for transformers of this configuration were among the main challenges of this project. Moreover, given their sheer weight and size, transportation was also a challenge.

Transformers are integral components of any electrical grid, and are a critical element in the efficient and safe conversion of energy across diverse voltage systems. ABB’s transformer portfolio includes power transformers rated up to 1000 kV, dry and liquid distribution transformers as well as related services and components.