ABB, Siemens and Areva are the main manufacturers of converter valves abroad. At present, the capacity of converter valves is: Xuji Group has the capacity of three converter valves, and Xi 'an Xidian Power Rectifier Co., Ltd. has the capacity of converter valves from Siemens and ABB. As a leading manufacturer of converter valves in China, Xuji Group has participated in the technology introduction and equipment manufacturing of all 13 DC transmission projects built and under construction in China since 1980s. The voltage level of converter valve ranges from 50 kV to 1 100 kV, including electrically triggered thyristor converter valve and light triggered thyristor converter valve. The product performance has reached the current international advanced level.