China has mastered UHV DC transmission technology and achieved "China's creation" and "China's leading"
China has comprehensively mastered key technologies such as UHV DC planning and design, experimental research, equipment development, engineering construction and operation management, and has been widely promoted and applied at home and abroad. The transmission capacity and transportation distance are continuously improved, and the advanced, reliable and economical. Sexuality and environmental friendliness have been fully verified, realizing "China's creation" and "China's leading". UHV DC transmission technology is of great significance for ensuring energy security and promoting the coordinated development of the eastern and western regions.
Electric power from the distant place, DC transmission innovation development
The direct current transmission is realized by high-voltage direct current, and the three-phase alternating current is rectified into direct current through the converter station at the sending end, and then sent to another converter station through the direct current transmission line to be inverted into three-phase alternating current, and sent to the receiving end. AC grid usage. The development of DC transmission is closely related to the development of converter technology (especially high voltage, high power converter equipment). China began to conduct DC transmission research in the early 1960s. In 1987, it built a Zhoushan HVDC transmission project with independent design and all domestic equipment. After more than 30 years of development, China's DC transmission project is leading the development of DC power transmission technology from voltage to capacity.
China's energy resources and power load demand are inversely distributed. 2/3 of the hydropower resources are concentrated in the southwestern region. More than 80% of the terrestrial wind energy resources and solar energy resources are concentrated in the western and northern regions, while more than 70% of the electricity consumption is concentrated in the eastern and central regions, and the energy base is 1000-4000 thousand away from the load center. Meter. In response to the characteristics of China's energy resources, the state has proposed a development strategy of “West-to-East Power Transmissionâ€.
Overcoming world-class problems and accelerating energy structure adjustment
UHV DC transmission system refers to a DC transmission system with a DC voltage rating of ±800 kV and above. The technical and economic analysis shows that when the transmission power is greater than 4 million kilowatts and the transmission distance reaches 1500 kilometers, by comparing the unit transmission distance and the annual cost indicator of the unit delivery capacity (annual cost per kilowatt hour, annual cost per kilometer), special High-voltage DC is a reasonable economic and economical choice. Through the development of UHV DC transmission, the advantages of power resources in the western provinces can be transformed into economic advantages, the energy and economic imbalances in the eastern and western regions can be changed, the energy structure adjustment in China can be accelerated, and the coordinated economic development of the eastern and western regions can be promoted. Providing external transmission channels for power resources in the Jinsha River, Minjiang River, and Yalong River, enabling large-scale development of hydropower resources in Sichuan, Yunnan, and Tibet in China; and clean energy such as wind power and photovoltaics in Xinjiang, Gansu, and Qinghai. Providing transportation channels to create favorable conditions for promoting energy supply side reform and energy structure transformation.
Compared with the conventional high-voltage direct current transmission system, the equipment manufacturing technology of the UHV DC system is difficult, especially the important converter equipment such as the converter transformer, the smoothing reactor, the DC bushing, the converter valve, etc., and it is necessary to overcome the manufacturing technology. Many difficulties. On January 8, the "UHV ± 800 kV DC transmission project" won the special prize of the National Science and Technology Progress Award. UHV ±800 kV DC transmission technology is the core technology of China's energy and power development, and is a key technology for implementing China's large-scale cross-regional energy optimization strategy. It has the characteristics of low transmission loss and high utilization rate of transmission corridors. The UHV ±800 kV DC transmission technology is extremely complicated, and there is no experience at home and abroad. The research and development is extremely difficult. More than 160 units such as State Grid Corporation and other scientific research institutes, universities, and equipment manufacturing have coordinated research, completed 141 key technology research, and created 37 world firsts. They have overcome the insulation characteristics and electromagnetic environment under extra high voltage and extra large current. World-class problems such as equipment development and test technology.
Seize the technical commanding heights to the UHV demonstration project
The ±800 kV UHV DC transmission system was built by China and successfully put into commercial operation. In 2006, China began to implement the UHV DC transmission demonstration project. In 2006, the Yunnan-Guangdong ±800 kV DC transmission project started, with a bipolar transmission power of 5 million kilowatts and a transmission distance of 1373 kilometers. On June 18, 2010, the bipolar was officially put into operation. Xiangjiaba-Shanghai (upward) ±800 kV DC transmission project, the maximum transmission capacity is 7 million kilowatts, and the transmission distance is 1907 kilometers. On July 8, 2010, Xiangjiaba-Shanghai ±800 kV UHV DC transmission demonstration project was put into operation.
Xiangjiaba-Shanghai ±800kV UHV DC transmission project starts from Sichuan Yibin Fulong Converter Station, and it is located in Shanghai Fengxian Converter Station, passing through Sichuan, Chongqing, Hubei, Hunan, Anhui, Jiangsu, Zhejiang, Shanghai and other six provinces. The two cities, across the Yangtze River four times, are the world's first UHV DC transmission project with a total length of more than 1900 kilometers.
The project is independently developed, independently designed and self-constructed by China. It is a world-class innovation achieved in China's energy field and represents the highest level of HVDC transmission technology in the world at that time. The project completed 129 major technical studies, and the comprehensive localization rate of equipment reached 68.52%. There are many assembly accessories, and the construction is difficult. There is no precedent in the world at the time of construction. The successful operation of the upward project marks that the State Grid Corporation has made comprehensive breakthroughs in ultra-long-distance and ultra-large-scale transmission technologies, laying a solid foundation for accelerating the large-scale development of clean energy in the western region of China and increasing the proportion of non-fossil energy; China has already possessed the comprehensive capability of production and system integration of complete UHV DC key equipment, which significantly improved the independent innovation capability and core competitiveness of China's electrical equipment manufacturing industry.
The world's most Jiquan ultra-high voltage direct current transmission project
Changji-Guquan (Jidong-Weinan) ±1100 kV UHV DC transmission project is the world's first DC transmission project with the highest voltage level, largest transmission capacity, the longest transmission distance and the most advanced technology. It is following Haminan-Zhengzhou± After the 800 kV UHV DC transmission project, the country implemented the second UHV transmission project of the “East Power Transmission†strategy, with a total length of 3,324 km. The engineering voltage level is ±1100 kV, and the rated transmission capacity is 12 million kilowatts. It starts from the Changji Converter Station in Xinjiang and ends at the Guquan Converter Station in Anhui Province. It passes through 6 provinces (autonomous regions) of Xinjiang, Gansu, Ningxia, Shaanxi, Henan and Anhui. .
The development of Jiquan engineering equipment is difficult. The converter valve, commutation transformer, DC wall bushing and flat-resistance voltage are raised to 1100 kV. The development faces the test of design, production process, test capability and method. The equipment has high requirements for autonomy, and the AC and DC main equipment is basically oriented to domestic procurement. The equipment is designed independently, independently researched and developed, and independently produced and supplied. The level of equipment autonomy should be further improved. After the project is put into operation, it can transfer 66 billion kWh of electricity to the East China region, reduce coal transportation by 30.24 million tons, reduce emissions of 24,000 tons of soot, 149,000 tons of sulfur dioxide and 157,000 tons of nitrogen oxides. Effectively promote the realization of air pollution control targets in the Yangtze River Delta region.
On March 29th, the Xinjiang section of the Changji-Guquan UHV DC transmission project was completed. On April 15th, with the last phase of the wire successfully crossing the Tianzhu Yangtze River, the ±1100 kV Yangtze River Great Crossing Project was completed. This is the first time that the ±1100 kV transmission line crosses the Yangtze River. Its main span tower is 225.2 meters high, and the single base tower weighs 1259 tons. It spans a total length of 2900 meters, all of which are the highest in the whole line. As of May 13, the main control building, relay room and bipolar low-end valve hall of Guquan Converter Station have been fully realized “dust-free†management, with cable laying completed 910,000 meters, accounting for 99%; bipolar low-end valve Hall converter valve and auxiliary equipment installation 80%; 1000 kV GIS equipment all special tests successfully completed, 1620 of 500 kV GIS equipment body installation unit, all completed.
Iron Battery,Nife Batteries Australia,Nife Battery 600Ah For Asutralia,Ni-Fe Battery 450~600Ah
Henan Xintaihang Power Source Co.,Ltd , https://www.taihangbattery.com