The total installed capacity of domestic pumped storage units has exceeded 30 million kilowatts

On January 1, the first unit of State Grid Xinyuan Anhui Jixi pumped storage power station was officially put into commercial operation, marking that the total installed capacity of domestic pumped storage units exceeded 30 million kilowatts.
The power station is located in Jixi County, Xuancheng City, Anhui Province, with a total installed capacity of 1.8 million KW. Six 300000 kW reversible mixed flow pumped storage units are installed. The power station hub is mainly composed of upper reservoir, lower reservoir, water conveyance system, underground powerhouse and ground switch station. The main project of the power station was started in December 2014, and all 6 units are planned to be put into operation in March 2021.

　　Anhui is an important hub in China's power layout, where more than 100 UHV and UHV lines form three dense channels. The "wind and rain" in Northwest China is transformed into electric energy, which is continuously transmitted to East China load center through Anhui Province. As we all know, "scenery" is a clean energy, which produces significant green benefits. To build a clean, low-carbon, safe and efficient energy system is the inevitable need of China's current development and the inevitable need of practicing the concept of green development. Pumped storage power station plays an irreplaceable role in large-scale development of clean energy power generation.
Jixi power station is the largest pumped storage power station with installed capacity in Anhui Province at present. It has the advantages of reliable operation, flexible start-up and fast regulation. It undertakes the tasks of peak load regulation, valley filling, frequency regulation, phase modulation and emergency standby in the power system, which can effectively suppress the fluctuation of power generation output of external power and "wind and solar" energy in UHV area, and help clean energy go online on a large scale, Improve the safe and stable operation ability and economic operation level of large power grid, and realize the optimal allocation of social resources as a whole.

　　Beautiful environment integrated into natural ecology of mountain stream
Jixi, located at the ridge of xuanhui, is the source of "Three Rivers" of Xin'an River, Shuiyang River and Qingge river. It is a national ecological county and an international green industry demonstration zone. It is the original intention and solemn commitment of the builders of Jixi power station to adhere to the concept of green development, devote themselves to the whole process of environmental protection and realize the integration of beautiful power station and natural environment.
During the excavation of underground powerhouse, a large amount of sewage containing oil and mud will inevitably be produced. Jixi hydropower station has realized zero discharge of sewage and avoided environmental damage to the downstream river caused by sewage outflow. A sewage treatment station with a daily treatment capacity of 1500 cubic meters is designed and built in the power station. Through a series of scientific treatment methods, such as adding oxalic acid mixed reaction, removing oil, adjusting pH value and sedimentation, the sewage can be turned into standard water with clear water quality, which can be recycled for sprinkling dust and greening irrigation. In addition, all the domestic wastewater of the power station is treated by the integrated sewage treatment device, achieving 100% standard discharge.
A winding mountain road should be built between the upper and lower reservoirs of the power station for the use of the project. In order to reduce the mountain excavation, the project adjusted the planning of the highway connecting the upper reservoir and the lower reservoir, and changed the original part of the open excavation into a tunnel, thus increasing the tunnel length by 498m. Although the engineering quantity is increased, 50 mu of woodland excavation is reduced, which effectively protects the surface vegetation along the way. Through discussion and research, the builders also optimized the construction layout of the project, reduced the temporary land of the transfer yard by 353.53 Mu compared with the original design, and protected the original ecology of the environment to the maximum extent.
In engineering construction, there are many such environmental protection measures. Jixi power station has invested 61.42 million yuan in environmental protection and restoration. Today, the rippling reservoir is located in the lush mountain stream, which seems to form a beautiful picture. The clear and transparent water will send green and clean electricity to thousands of households.
Green energy drives local economic development
After Jixi power station is completed and put into operation, it will use the rich power of the large power grid to pump into the upper reservoir, store it in the form of potential energy, and discharge water to generate electricity when the power grid needs it. Through scientific and reasonable dispatching operation, it can promote the absorption of external power and new energy in East China Power Grid and Anhui power grid, and promote the transformation and structural adjustment of China's power industry.

Photo by Shu Shanlong of lower reservoir of Jixi Hydropower Station

　　During the construction period of Jixi power station project, it provided a large number of local jobs and contributed more than 140 million yuan to local taxes. After the power station is put into operation, 216000 tons of standard coal, 475000 tons of carbon dioxide, 1079 tons of nitrogen oxides and 2879 tons of sulfur dioxide can be saved every year.
Xiaoyao village beside the upper reservoir of the power station is very inconvenient due to its geographical location. The 13 km highway connecting the upper reservoir and the lower reservoir built by Jixi hydropower station not only meets the needs of engineering construction, but also greatly improves the travel conditions of more than 1000 villagers in Xiaoyao village, reducing their downhill time from more than two and a half hours to about half an hour. The villagers were very happy when they mentioned this road. It turned out that there was a happy event in the village and they had to leave after noon. And now after dark, the mountain road can go, and the transportation cost of the village has been reduced.
Technological innovation highlights the quality of made in China
Jixi power station is the first 650 meter ultra-high head, high speed, large capacity reversible unit independently developed, designed and manufactured in China. During the trial operation of the first unit, the data of each index is excellent, which shows the quality of made in China.
The innovative design of "one shaft + integral yoke" is adopted for generator motor, which can improve the overall stability of the unit and greatly save the installation time on site. The rotating parts with total height of 17.73 meters and total weight of 480 tons rotate at a high speed of 500 revolutions per minute. The maximum swing is only 65 microns, and the maximum vibration amplitude (measured at the top cover and upper and lower frames) is only 12 microns.
For the first time, the independent R & D runner adopts long and short blades, the stator core adopts elastic locating ribs, and the thrust bearing adopts low liquid level and low loss spray bearing, which further improves the stability of the unit and greatly reduces the electromagnetic noise and oil mist pollution.
The research on automatic welding technology in 800MPa steel pipe welding of power plant water diversion system has improved the stability of welding quality and welding efficiency of penstock, and provided demonstration and guidance for the industry. The first pass rate of weld is 100%, and the welding efficiency of single weld can be doubled. By comparing automatic welding with traditional manual arc welding, a single weld can save about 1250.9 yuan. According to the calculation of 942 circumferential joints in steel pipe installation of Jixi power station, only this technology can save 1178000 yuan.
It is reported that during the construction period of Jixi power station, it has won one third prize of scientific progress award of electric power construction; one third prize of science and technology progress award of State Grid; one first prize and one second prize of provincial and ministerial QC and construction method; five other provincial and ministerial QC achievement awards and four new construction methods; five invention patents and 34 utility model patents.
In the new era of beating drum and stirring up new banner and raising new journey, the national Power Grid Corp always adheres to the New Socialist Strategy of socialism with Chinese characteristics under the guidance of Xi Jinping's new era, and thoroughly implements the new strategy of energy security of "four revolutions and one cooperation", and is committed to innovation and responsibility, practicing the new historical orientation of "six forces" of state owned enterprises and accelerating China's "starting point". The construction of "three types and two networks" world-class energy Internet enterprises is a leader and a model in ensuring national energy security, serving economic and social development and people's better life.