ABB said it has successfully developed and tested an 1100 kV "ultrahigh-voltage" direct current converter transformer, breaking the record for the highest DC voltage levels ever, and facilitating more power to be transmitted efficiently over longer distances.

The Xiangjiaba-Shanghai link, commissioned by ABB was the world`s first commercial 800-kV "UHVDC" connection. It has a capacity of 6400 MW and covers a distance of just over 2000 km, making it the longest of its kind in operation. The new 1100-kV converter transformer technology will make it possible to transmit more than 10,000 MW of power across distances as long as 3,000 km.

Higher voltage levels allow larger amounts of electricity to be transported across long distances with minimal losses using HVDC technology. Converter transformers play a critical role in HVDC transmission serving as the vital interface between the DC link and the AC network. Development of the 1100-kV transformer addressed several technology challenges such as the sheer size and scale, electrical insulation including bushings and thermal performance parameters.