Issue 14/12 HVDC/FACTS - Highlights 5000A DC Siemens commutation breaker successfully tested in China Cutting-edge DC commutation breaker ensures reliable operation to supply sustainable power to China’s megacities in the delta area of Yangzi River. Siemens DC commutation breaker for the highest rated DC current of 5000A passed successfully the switching test at the Shuanglong converter station Sichuan in China. Siemens supplied DC commutation breakers for the ultra-high-voltage direct-current (UHV DC) transmission project Xiluodu-Zhejiang from the purchaser State Grid Corporation of China. In January 2013 Siemens got the order to supply special DC equipment at 5000 ampere (A) rated current level such as wall bushings, bypass breakers and DC commutation breakers with their local partner XD Xian for this 8 gigawatt (GW) UHV DC project with one of the most powerful transmission lines in the world. Starting operation in July 2014 the 1670 kilometer (km) power link transports clean hydropower at a voltage level of ± 800 kilovolts (kV) from Xiluodu hydropower station in Sichuan province to the highly industrialized Zhejiang province. The test took place during the high-water level season to provide the necessary power from the hydro power plant. “Siemens DC Commutation Circuit Breaker has been successfully tested in operation at full load at 5000A DC in Sichuan China. Siemens has proven the switching capability without current flow reduction for the currently biggest UHV DC transmission,” says Cristen Schimpf, Vice President for High-Voltage DC Transmission Solutions. Fig. 1: Site view of the converter station Sichuan, China http://www.siemens.com/FACTS http://www.siemens.com/HVDC