China’s First 20 kV “Petal-shaped” Power Distribution Network with Wide-area Protection Technology

On September 5, 2016, the 20 kV Zhenghan Switching Station started transmitting power and the 20 kV power distribution network for the Sino-Singapore Knowledge City in Guangzhou realized closed-loop operation, marking the official operation of China’s first 20 kV “petal-shaped” power distribution network with wide-area protection technology. With a reliability rate of over 99.999%, it can truly realize uninterrupted power supply. At present, the annual average outage time for consumers in the Sino-Singapore Knowledge City is within 5 minutes, which is of the international top level; in the future, the average outage time can be reduced to less than 1 minute, on a par with power grids in other major cities around the world.

As it is planned, the power grid of the Knowledge City contains 9 220kVsubstationsand 1 110kV substation. Currently the “petal-shaped” power distribution network is of 20kV a direct step-down from the 110 kV Yunping Substation. It is also Guangzhou’s first 20 kV power distribution network. Apart from the “petal-shaped” network, Guangzhou Power Supply Bureau also extensively applies wide-area protection and other advanced technologies which were adopted in major networks of over 220 kV and now are first applied in a 20 kV network in China. When there is a breakdown, the network can automatically and efficiently isolate the malfunction and restore the power, serving as an extra protective layer upon the power grid of the Knowledge City.