ABB, a power and automation technology group, has successfully developed and tested an 1,100 kilovolt (kV) ultrahigh-voltage direct current (UHVDC) converter transformer breaking the record for the highest DC voltage levels ever. The Xiangjiaba-Shanghai link, commissioned by ABB is the world's first commercial 800 kV UHVDC connection. It has a capacity of 6,400 MW and covers a distance of around 2,000 km, making it the longest of its kind in operation. The new 1,100 kilovolt (kV) converter transformer technology will make it possible to transmit more than 10,000 megawatts (MW) of power across distances as long as 3,000 km.
Higher voltage levels allow larger amounts of electricity to be transported across very 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 1,100 kV transformer addresses several technology challenges such as the sheer size and scale, electrical insulation including bushings and thermal performance parameters.