ABB certifies first 1100kV DC transformer

December 14, 2017 // By Nick Flaherty
ABB has certified the low and high voltage units of the world’s most powerful ultrahigh-voltage direct current (UHVDC) transformer.

The ±1,100 kV (1.1 million volts) UHVDC transformer was developed and manufactured with the State Grid Corporation of China (SGCC). The successful type tests pave the way for the implementation of the Changji-Guquan UHVDC link, which will transmit power from the Xinjiang region in the Northwest, to Anhui province in eastern China.

Changji-Guquan is the world’s first ±1,100 kV UHVDC link and will set a new world record in terms of voltage level, transmission capacity and distance. It will be capable of transporting 12GW of electricity - the equivalent of 12 large power plants and 50 percent more than the ±800kV UHVDC links currently in operation. The transmission distance will be extended from around 2,000km to over 3,000km, enabling the integration and transmission of remote renewables on a much larger scale.

When fully operational this UHVDC link will be able to feed eight 500 kV and two 1,000 kV AC lines – delivering power equivalent to twice the average annual power consumption of Switzerland. ABB’s technology also makes it possible to connect ±1,100 kV DC with 750 kV UHVAC links for the first time. In addition to the transformer, ABB has also developed and successfully tested a range of other key ±1,100 kV components, including converter valves, bushings and DC circuit breakers.

“In addition to transporting more power across longer distances with lower losses, this breakthrough will enable the interconnection of AC and DC grids and support the future linking of regions and countries.” said Claudio Facchin, president of ABB’s Power Grids division. “It reinforces our pioneering technology leadership in HVDC transmission and reaffirms our close collaboration with SGCC, as we enable a stronger, smarter and greener grid.”

“The Changji-Guquan ±1100kV project is a major technical step-up making it the world’s highest DC voltage. The transformer is a key element of this link and we are pleased that the first of these landmark transformers have passed critical tests and exceeded expectations,” said