CSG Successfully Develops the World’s First Flexible UHVDC Converter Valve

Guangzhou - China Southern Power Grid Co., Ltd. (CSG) is proud to announce that it has successfully developed the world's first UHVDC converter valve, the result of dedicated national key research and development project on "high-voltage high-capacity flexible DC transmission key technology research and engineering application demonstration".

The project, undertaken by CSG, is the world’s first in applying flexible DC technology to ±800 kV ultra-high voltage converter valves, increasing power transmission capacity to 5 GW and providing a firm foundation for the implementation of flexible DC technology in the ±800 KW Wudongde – Guangdong DC Transmission Project and its follow-up UHV DC transmission projects.

The converter valve, the heart of flexible DC transmission and bridge for DC/AC conversion, represents the most advanced technology and yet is the most challenging part of all the flexible DC equipment.req

The project has integrated switching devices and capacitance components into power modules and constructed a 800 kV large valve tower in a building-block approach. These valve towers are 15 meters high, nine meters long and seven meters wide, weighing approximately 70 tons, which is the weight of a large passenger aircraft.

The Wudongde - Guangdong DC Transmission Project will require more than 70 such large valve towers. Since the proposal of this project last September 2016, CSG has clarified its theoretical position on and methods for UHV flexible DC, proving the feasibility and demonstrativeness of flexible DC in the Wudongde – Guangdong DC Transmission Project, and has carried out physical tests on mixed DC for the first time anywhere.

The project has attracted wide attention in the international power grid field and demonstrated China Southern Power Grid’s worldwide leadership role in power technology development. CSG cannot only provide the technical support for the feasibility study and monographic study in the early stage of such demonstration projects, but also support the implementation of each  follow-up project.