Power supplies could be restored within a hundred milliseconds following the opening this week of a DC power distribution centre by China’s State Grid Jiangsu Electric Power.

The Pangdong station functions for AC-DC conversion and power distribution, acting as one of the two hearts for State Grid Jiangsu’s demonstrative low and medium voltage (LV and MV) distribution project, which is expected to become a world leading distribution system with the largest scale, complete voltage levels and technical equipment when it is completed this August.

Listed as a national key R&D project in 2018 with construction starting last May, the demonstration project was undertaken by State Grid Jiangsu. It has built two DC central stations in Pangdong and Jiuli within the Wujiang economic development zone in Suzhou city of east China’s Jiangsu province. The LV and MV DC system covers municipal, industrial, commercial and household uses.

With an accumulative DC load of 10.5MW, the system is capable of different DC output at 10kV, 750V and 375V for meeting different power demands. The station could, for example, convert 10kV AC into 10kV DC, and deliver, upon demand, different voltage level DC through a transformer, according to Yang Chen, deputy director of the operation and inspection department with State Grid Suzhou Power Supply Company.

The Pangdong station is also the control centre of the entire distribution system, said Yang Chen, noting that power supply can be restored within 100ms in case of network failure thus increasing power supply reliability rate to 99.999 per cent with the latest control and coordination system.

The project so far has made breakthroughs in areas of system planning and design, equipment development, operation control technology and system protection technology, with 93 patents accepted and 12 software works registered, as well as complying with six domestic and foreign standards.

The demonstration project is expected to explore the construction, operation and maintenance model for integrated DC power distribution and use, and provide experience for global energy transformation and power consumption changes, according to Yuan Dong, deputy director of the equipment department of State Grid Jiangsu.