Recently, the main transformer capacity upgrade project at the 500-kilovolt Rizhao Substation, constructed and managed by State Grid Shandong Electric Power Company, has commenced.
The existing Rizhao Substation has two main transformers with a total capacity of 1.25 million kilovolt-amperes. The station has been in operation for over 20 years and faces problems including numerous interfaces between old and new equipment, great difficulty in secondary system compatibility, and complex multi-round power outage transition organization.
The main transformer capacity upgrade project includes replacing the original 500-kilovolt-ampere No.1 main transformer of the station with a 750-kilovolt-ampere main transformer, increasing the total substation capacity by 20 percent. It also adjusts the 220-kilovolt wiring from single busbar with single section to double busbars with double sections, builds 3 new busbar section bays and busbar equipment bays, replaces the No.1 busbar section bay, replaces 4 sets of 500-kilovolt disconnect switches and 3 sets of 35-kilovolt disconnect switches, and builds new 220-kilovolt relay rooms, pump houses, fire water pools, accident oil pools, and other facilities.
For the 220-kilovolt busbar retrofit, State Grid Shandong Electric Power has innovatively proposed a “partial gas-insulated switchgear / mixed gas insulated switch equipment embedding solution” to achieve “minimally invasive” replacement. Meanwhile, combined with the commissioning sequence of the 220-kilovolt Yuanhe-Wulian double-circuit lines, the strategy of “removing part of the bus duct + temporary external short-circuiting” has been adopted to maximize the guarantee of continuous and reliable operation of the Rizhao power grid.
After the project is completed and put into operation, it will further meet the rapidly growing electricity load needs in areas such as northern Donggang District, northern Lanshan District, Wulian County, and Juxian County in Rizhao, optimize the regional power grid structure, significantly improve power grid supply capacity and reliability, and provide solid power support for local economic and social development.
Source:Bjx Power Grid