In July 25th, the national Power Grid Corp held a teleconference on the construction of Huainan Nanjing Shanghai 1 million volt high voltage AC transmission and transformation project in Beijing, indicating that the project entered the stage of construction and implementation. Shuai Junqing, deputy general manager of the national Power Grid Corp, pointed out at the meeting: "Huainan Nanjing Shanghai AC UHV will be connected with several UHV and conventional DC projects, so we need to study and master the core technology of UHV AC / DC hybrid power grid safe operation."
The most difficult exchange of UHV to date
Huainan - Nanjing - Shanghai UHV AC project approved by the state in April this year, China is following the Jindongnan Nanyang Jingmen, Huainan, Zhejiang, Zhejiang - Shanghai - Fuzhou UHV construction of fourth UHV AC project, atmospheric pollution prevention action plan is determined by the state 12 key transmission channel the first approved UHV engineering. The project includes three substations in new Nanjing, Taizhou and Suzhou, and two substations in Huainan, Shanghai and West. The transformer capacity is 1200 KVA, the new transmission line is 2 * 779.5 km, and the authorized investment is 26 billion 110 million yuan. Engineering substations and general lines will be built in June 2016, and Sutong great leap forward will strive to be completed in December 2016.
Shuai Junqing pointed out: "Huainan - Nanjing - Shanghai AC UHV is the largest and most difficult UHV exchange project to date." The project is based on 22 counties and cities in two provinces and one city in Anhui, Jiangsu and Shanghai. The 36 km line in Shanghai is set up with 500 thousand volts, 220 thousand volts and four towers on the same tower, and the other lines are erected on the same tower. At the same time, the Sutong Yangtze River Crossing across the whole tower nearly 400 meters high, weighing more than 10000 tons of single base, single base concrete nearly 200 thousand cubic meters, is currently the world's largest, the highest technical difficulty in crossing engineering in all aspects of design, manufacturing, construction and other technical problems are facing new.
Han Xiancai, the vice director of the Power Grid Corp's national exchange department, also introduced: "the route through the East China economic hinterland, through the densely populated areas of population and factories and mines, is 16 times crossing the railway, 58 times of highways and highways. There are many safety risks and difficulties in implementation. In addition, the main equipment and materials of the project are also facing the situation of simultaneous manufacturing with multiple UHV projects, facing the great pressure of effective capacity shortage and mass production quality stability control, and all aspects of quality resources such as design, construction, supervision and manufacturing are also tightening up.
Formation of UHV AC double ring network
According to reports, the Huainan - Nanjing - Shanghai UHV AC will be linked with the number of UHV and conventional HVDC project, especially with the Zhejiang Anhui power transmission - Huainan - Shanghai UHV AC (put into operation in September 2013), north of Zhejiang - Fuzhou UHV AC (put into operation before the end of this year) to build a UHV AC ring and by the end of the grid, will for the first time in the world to form a total length of 1428 kilometers, connecting the energy base and the load center of UHV AC double loop network.
The transmission capacity of UHV AC ring network will reach 8 million to 10 million kilowatts, so we need to master the core technology of UHV AC / DC hybrid power grid's safe operation. Shuai Junqing pointed out that "UHV AC double loop network to improve the power exchange capacity of East China Power Grid and the external power internal acceptance ability, enhance the ability of network security and stability and strengthen the level of East China power grid to withstand major accidents, to meet the sustainable growth in Jiangsu, Shanghai area electricity demand, and implement the action plan for air pollution prevention and control, promote sustainable economic development it is very important."
It is also reported that the three phase transmission of Pingwei Power Plant UHV project with the Huainan - Nanjing - Shanghai UHV construction period. In June this year, the project has been approved by the state, which is China's first power plant up to 1 million volts direct access to the power grid project, not only play an important role in Pingwei Power Plant sent power, but also has an important demonstration significance in technology.
UHV enters the stage of large-scale development
As of now, the national Power Grid Corp completed a total of two pay four straight UHV, yijianhuzaijian transmission line length of more than 10 thousand kilometers, the substation (converter) capacity of more than 1 million KVA (kw), the full realization of the UHV transmission from theory, technology, equipment, construction to the full range of breakthrough operation the. When the accumulative power supply is 165 billion kwh, the power transmission advantage of ultra high voltage, large capacity and low loss is brought into full play.
Shuai Junqing pointed out: "UHV power grid has entered a new stage of comprehensive large-scale construction and accelerated development." At present, UHV transmission in ensuring energy security, energy efficiency, governance haze, and serve the economic and social development in an important role has formed a broad consensus, UHV transmission has been included in the "12th Five-Year" energy development plan, the State Grid Corporation "four pay four straight 8 UHV projects included in the national air pollution control action plan. According to the "air pollution prevention and control transmission channel construction task" signed by the national Power Grid Corp and the national energy administration, it will be built into the "four to four straight" UHV project in 2017.
