BEIJING, April 30 (Xinhua) -- Yangzhou-Zhenjiang DC power transmission project, the first project to convert in-operation AC transmission lines to DC ones in China, was put into service in east China's Jiangsu Province on Sunday.
Without changing the main structure of the cross-Yangtze River transmission towers, State Grid Jiangsu Electric Power Co., Ltd. upgraded transmission lines between the two cities at different sides of the river to improve transmission capacity of existing grids.
As a reproducible example, the project means much for areas with a large population but limited space for new grids construction as related AC-DC conversion technologies can solve long-distance power transmission problems between regional power grids and save much costs, said Chen Songtao, planning and management director with construction department of State Grid Jiangsu Electric Power Co., Ltd.
Currently, power transmission to south Jiangsu from north Jiangsu dotted by new energy power projects relies mainly on six cross-Yangtze River transmission corridors. But increasing power transmission demand and stricter Yangtze River ecological protection make new corridor building less likely and improving transmission capacity of existing corridors is more imperative now.
Compared with AC power transmission lines, DC ones of same voltage have greater transmission capacity and lower transmission loss and through AC-DC conversion, the Yangzhou-Zhenjiang transmission lines now boast a transmission capacity of 1.2 million kW, introduced Chen.
Apart from capacity expansion, AC-DC conversion of transmission lines have multiple advantages such as high reliance and economic efficiency. Taking the cross-Yangtze River section as an example, its construction period was 5-6 months shorter than that of building new transmission lines and related investment dropped by nearly 60 million yuan, added Chen.
Using smart robots to achieve highly efficient and green construction, State Grid Jiangsu Electric Power saw related efficiency much improved than traditional manual construction. Xu Huaiyu, vice chief engineer of the project said a batch of engineering resolutions for long-distance transmission line change and nine innovation achievements have been developed independently by the company to facilitate the following construction.
After completion of phase II and III of the project, its transmission capacity is likely to reach 3.60 million kW and further satisfy the power transmission demand in Jiangsu.
(Edited by Duan Jing with Xinhua Silk Road, duanjing@xinhua.org)
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