Key words: Zhangbei, Beijing, Winter Olympic Games, Flexible direct drive

Abstract: On June 25, ±500kV Zhangbei flexible DC power grid test demonstration project was successfully connected with four terminals. The clean energy power generation in Zhangbei area has been successfully connected to the Beijing power grid and sent to the venues of the Beijing Winter Olympic Games.

Text:

The ±500 kV Yanqing, a northwestern district of Beijing, converter station is an important receiving terminal converter station of Zhangbei， Zhangjiakou, Hebei province, flexible direct transmission project, a key supporting power grid project for Beijing Winter Olympics. Clean electricity such as wind power and photo-voltaic power from Zhangjiakou will be sent to Beijing Winter Olympic stadium from here.

The Zhangbei Flexible DC project can provide 14.1 billion kwh of green power, equivalent to one tenth of Beijing’s annual electricity consumption. It can guarantee 100% green power supply for all winter Olympic venues during the 2022 Beijing Winter Olympic Games.

The project has a rated voltage of ±500kV, a 666km ± 500kV DC transmission line, and four new converter stations with a total converter capacity of 9 million KW. It can connect the abundant wind power, photo-voltaic power generation and other energy sources in Zhangbei area, and overcome the intermittent and unstable problems of renewable energy power generation by taking advantage of the complementarity between wind power, photo-voltaic energy, energy storage and other energy forms to realize the collection and delivery of 10 million kilowatt level new energy base in Zhangbei, and effectively support the realization of 100% clean energy power supply for the 2022 Beijing Winter Olympic Stadium.

The core technology and key equipment of the project are all initiated internationally. The project has three breakthroughs and will create 12 world firsts.

Three Breakthroughs

• Breakthrough in flexible DC networking technology for the first time.
• For the first time, the transmission capacity of flexible HVDC is raised to the level of conventional HVDC.
• For the first time, the reliability of flexible DC is improved to the level of conventional DC.

12 World Firsts

• the first DC power grid with real network characteristics in the world;
• the world’s first large-scale wind power and photo-voltaic isolated island transmission DC power grid project with true bipolar connection;
• the first DC power grid in the world to realize multi energy complementary of wind, light and energy storage;
• the world’s first DC power grid with overhead transmission lines;
• the world’s first DC power grid with metal return line as neutral line;
• the first multi-dimensional and multi factor control and protection system based on DC power grid in the world;
• flexible DC converter station with the highest voltage level and maximum capacity in the world (± 500kV, 3000MW);
• DC circuit breaker with the highest voltage level and maximum breaking capacity in the world (535kv, 25kA, 3MS);
• flexible DC converter valve (535kv, 3000MW) with the highest voltage level and maximum commutation capacity in the world;
• the world’s largest capacity AC energy consumption device (8 × 375mW);
• DC cable with the highest voltage level and maximum transmission capacity in the world (535kv, 3000A);
• the world’s largest power fully controlled turn off device (4.5kv, 3000A high power IGBT).

Source: 北极星风力发电网

Translated and edited by:minds:connected