Siemens Power Transmission and Distribution (PTD) has won an order from China Southern Power Grid Company, Guangzhou, to construct a high-voltage DC transmission (HVDC) system between the province of Yunnan in the southwest corner of China and the province of Guangdong on the south coast of the country together with Chinese partners. With this technology, Siemens ventures into a new dimension of HVDC technology. The system will be the first in the world to transmit electricity at a DC voltage of +/- 800 kV. At the same time this project with a power transmission capacity of 5000 MW will be the long-distance HVDC link with the world’s highest ever power capacity which has been built. The Siemens value of the order in total is more than 300 million euros. The system is scheduled to commence commercial service by mid-2010.
The additional electric power from Yunnan is intended to supply the rapidly growing industrial region of the Pearl River delta in the province of Guangdong and the megacities of Guangzhou and Shenzhen. In future the electricity generated by several hydro-electric power plants will be transported from Yunnan via 1,400 km to Guangzhou over this long-distance HVDC link. Hydro-electric power generation is economically, environment-friendly and does not emit any CO2. This HVDC link will save the emission of more than 30 million tons of CO2 a year. That is how much of the gas which is harmful to the climate would be produced otherwise, for example through the construction of additional fossil fired conventional power plants in the province of Guangdong to serve the regional grid.
“This outstanding order shows that our efforts over recent years to further develop 800 kV HVDC technology to the point where it is ready for use in projects have been worthwhile. Today, we can provide it to our customers,” said Dr. Udo Niehage, President of Siemens Power Transmission and Distribution Group (PTD).
Together with Chinese partners, Siemens will design the complex HVDC system and supply the main HVDC components in addition to ten 800-kV and ten 600-kV converter transformers as well as DC filters and 800-kV DC components. Furthermore Siemens supports its Chinese partners in design and manufacturing of thyristor valves, converter transformers and control systems. The converter stations operate in bipolar mode with two series-connected, twelve-pulse valve groups per pole, in which light-triggered thyristors are used. This scheme improves the reliability and flexibility of the power transmission.
