The State Grid Corp. of China (SGCC) has chosen ABB to supply converter transformers and high-voltage equipment for the SGCC's 800-kV, ultrahigh-voltage direct current (UHVDC) transmission link, in China's Shaanxi and Hubei provinces, in the Northwest and Central regions of the country.
The 1100-km-long Shanbei-Wuhan link will transport up to 8000 MW of electricity, enough to meet the needs of around eight million people in China. The orders were booked in the first and second quarters of 2019.
Converter transformers receive electricity from nearby power stations and increase their voltage to extremely high levels, in order to transport it over long distances and with minimal losses. Near to the end consumer, similar transformers will decrease the voltage in order to ensure distribution to the local grid. High-voltage equipment includes breakers that protect the grid from disruptive faults, and capacitor banks that improve the quality of electricity supply, thus increasing the product lifespan and helping to reduce losses.
At 8000-MW transmission, the Shanbei-Wuhan link will be among the world’s most powerful and is an important step for the SGCC in developing global UHVDC systems standards. They will interconnect electrical grids of regions, countries, and continents to efficiently transport clean power in large volumes over long distances.
UHVDC uses dc electricity at extremely high voltages that can have as much as 40% lower losses than an equivalent conventional ac system. This means far less energy is wasted, more power reaches end users, and carbon dioxide (CO2) emissions come down. In this case, savings of up to 1 to 2 million tons of CO2 emissions per year can be expected.
"The ultrahigh-voltage (UHV) transmission equipment from ABB is an important milestone in realizing the SGCC’s vision of building stronger and greener grids. These UHV super-grids will enable the reliable integration of ever more power sources from remote areas into the power grids of urban centers," said Claudio Facchin, president of ABB’s Power Grids business.
