China's Shandong 1,197-kilometer Yantai-Weihai UHV Project Commissioned, Forming the Country's First Provincial-Level Dual-Ring Network

en.Wedoany.com Reported - On October 10, the Yantai-Weihai 1,000 kV UHV AC power transmission and transformation project in Shandong, China, was fully completed and commissioned, forming China's first provincial-level UHV AC dual-ring network. The project has a total single-circuit-equivalent length of 1,197 kilometers, passing through five cities—Yantai, Qingdao, Rizhao, Weifang, and Linyi—and includes one newly built 1,000 kV switching station, two expanded substations, and 2,124 erected transmission towers. Hubei Engineering Company, Hebei Institute, and Jiangxi Hydropower Company under PowerChina participated in the project's design and construction. The project is also China's first UHV AC power transmission and transformation project commissioned during the "15th Five-Year Plan" period.

The project commenced in June 2025 and is China's first UHV project involving simultaneous construction in mountainous and marine areas, with 822 towers located in hilly and mountainous sections and 17 towers involving marine construction. The Haiyang West Switching Station adopts a "one site, two stations" layout, with the 1,000 kV gas-insulated metal-enclosed switchgear (GIS) having a linear length of nearly 600 meters, planning for 12 1,000 kV outgoing lines, and reserving conditions for expanding two main transformers, capable of connecting power from two nuclear power plants. The project also applies domestically produced low-noise high-voltage reactors.

Hubei Engineering Company undertook the design of Line Package 6 and the supervision of Package 3. The supervised line involves the three cities of Yantai, Qingdao, and Weifang, covering 468 towers and 237.5 kilometers of stringing work. During the design process, the team adopted corrosion-resistant conductors and towers with thickened galvanized coatings for highly corrosive areas, optimized foundation pile diameters in hard rock shallow-buried sections, and used micro-pile foundations for some mountainous tower positions. The line is also equipped with integrated aviation obstruction lights to reduce the risk of wear on external power lines.

Hebei Institute was responsible for the design of Line Package 3, with the entire line located within Yantai City, and a double-circuit line length of 2×87.668 kilometers. The design work involved obstacles and important crossings such as airports, wetland parks, and water source areas, and foundation types were adjusted according to geological conditions along the route. To meet the demand for future connection to Dengzhou Station, the design adopted a permanent-temporary combined scheme; in the Laiyang Wulong River wetland area, bird-deterrent warning balls were installed on some ground wires.

After the project is commissioned, Shandong's existing UHV grid and the Yantai-Weihai transmission corridor will form a "figure-eight" dual-ring structure, connecting to the Jiaodong Peninsula's nuclear power and wind-solar power generation bases. According to Shandong's power grid plan, by the end of the "15th Five-Year Plan," the maximum surplus power export demand in the Yantai-Weihai area is expected to exceed 30 million kilowatts.