Beijing, China, July 7, 2015 - The ±800kV/6250A valve developed by SGRI passed all the type tests on June 28, 2015. The newly launched valve has the highest current-carrying capability of its kind in the world, and features higher transmission efficiency and lower cost per MW; it could increase power transmission capacity up to 10GW, a 25% increase compared to ±800kV/5000A valve.

The R&D of ±800kV/6250A valve was carried out based on an earlier version of ±800kV/5000A. The ±800kV/5000A valve was developed in 2010, and has been employed in four UHVDC projects, including Jinping-Sunan project, Xiluodu-Zhejiang project, Southern Hami-Zhengzhou project and Lingzhou-Shaoxing project. Except for 7.2GW Jinping-Sunan project, the other three are all rated at 8GW.

When transmitted power is increased above 8GW, ±800kV/5000A system becomes less economic. Larger capacity UHVDC system is demanded, either by increasing voltage level (e.g. 1100kV) or at existing voltage ratings with higher current-carrying capabilities (e.g. 6250A). SGRI has finished complete type test of ±1100kV UHVDC converter valve early this year, the ±800kV/6250A valve pushes forward the UHVDC technology from current perspective. Through insight research SGRI has overcome difficulties like loss control under larger current, component heat dissipation and even temperature control, as well as EMC design, etc.

The ±800kV/6250A valve comes out just in time as two target projects will call for bids this year. Next, SGRI will work towards the engineering research for project demonstration and further support SGCC’s construction of UHVDC backbone network. pan lang=EN-US style='font-size:12.0pt;mso-fareast-font-family:宋体;mso-bidi-font-family:Calibri; mso-bidi-theme-font:minor-latin;color:black;mso-font-kerning:0pt'>So far, this platform has been utilized for Shanghai Nanhui and Xiamen VSC-HVDC project for system study as well as R&D and test of valve control and station control equipment. The state-of-the-art development has opened new doors for power system dynamic simulation and taken China to a new level in the field of HVDC simulation.

Next, SGRI will work towards the construction of a more ambitious DC grid simulation system and support the development of SGCC’s Strong Smart Grid.