The Yunnan-Guangdong HVDC link is operating at a transmission voltage of 800kV. Commissioning of the second pole and thus startup of the entire system is scheduled for mid-2010.

China has raised the DC voltage of its new long-distance HVDC links to 800kV in order to further reduce transmission losses and to be able to bridge greater distances.

This high-efficiency HVDC system can reduce annual CO2 emissions by over 30 megatons, which would otherwise have been produced by additional fossil-fueled power plants linked to the interconnected grid in Guangdong Province, Siemens said.

Niehage, CEO of power transmission division at Siemens Energy, said: “Successful commissioning of the first pole of currently the world’s most powerful HVDC system shows that our efforts to get 800kV HVDC technology ready for concrete projects have paid off. As technology leader in this field we have thus set new benchmarks.”

Together with its Chinese partners, Siemens designed the entire HVDC system for the Yunnan-Guangdong project and supplied the core components, which included 800kV and 600kV converter transformers, DC filters and 800kV direct-current components.