江苏春晨电缆有限公司：https://www.ybzhan.cn/st82365/
(750) kV and other voltage levels. Extra high voltage power transmission is refers to the AC 1 million volts or DC + 800 thousand volts.
超高压直流输电的优点和特点
Advantages and characteristics of ultra high voltage DC transmission
Large transport capacity. A high voltage direct current transmission project has been built in the world with a number of 3GW. Power transmission distance. High voltage direct current transmission project with transmission distance up to 1700km in the world. China GE Nan (Gezhouba Dam - Shanghai Nanqiao HVDC project) the transportation distance is 1052km, Tian Guang (Tianshengqiao Guangdong), three (three - Changzhou), three (Three Gorges Guangdong), Guiyang Guangzhou (Guizhou - Guangdong), HVDC transmission distance are close to 1000km. The size and direction of the transmission power can be controlled and adjusted quickly. The DC transmission access will not increase the original short-circuit current capacity of the power system, nor by system stability limit. The DC transmission line corridor can make full use of resources, the corridor width is about half of the AC transmission line, and large transmission capacity, power supply unit corridor width is about 4 times of exchange. Such as DC + 500kV line corridor width of about 30m, the transmission capacity of 3GW; while the AC 500kV line corridor width of 55m, the capacity of the transmission capacity is only 1GW. The DC cable line is not troubled by the capacitance current of the AC cable line, without the magnetic induction loss and the dielectric loss, and basically only the core wire resistance loss, and the insulation level is relatively low. One of the HVDC pole fails, another can continue to run and play through overload capacity, can keep the transmission power or reduce transmission power loss. The DC system itself with modulation function, can respond according to the requirements of the system to produce damping of electromechanical oscillation, damping low-frequency oscillation, improving power system transient stability. We can through the reactive power control of AC voltage regulation system of converter station configuration. We can through the reactive power control of AC voltage regulation system of converter station configuration. Between the large power grid interconnected by DC transmission (e.g., back-to-back way) between the 2 power grid will not interfere with each other and influence, when necessary, can quickly exchange power.
特高压直流输电的特点
Characteristics of extra high voltage DC transmission
UHV DC transmission characteristics: high pressure, up to + 800kV. The voltage of the equipment, such as high voltage (+ 800kV) put forward the high requirements of the converter transformer and bushing, bushing, lightning arrester insulation subjected to R & D; + 800kV, such as porcelain column, line insulator etc. the need for new development. Large power transmission capacity. The transmission capacity of UHV DC transmission project is as high as 5GW and 6.4GW, and the corresponding DC rated current will reach 3125A and 4000A. Power transmission distance is long, up to 1500km, or even more than 2000km.
特高压输电技术的优越性
The construction of UHV power grid as the strong smart grid backbone network, will greatly improve the efficiency of long-distance and large capacity transmission, reduce the transmission loss, reduce the transmission cost, achieve the optimal allocation of energy resources in larger scope, to promote the efficient development and utilization of energy in china. UHV transmission for the implementation of national energy strategy to ensure energy security, to promote sustainable development of the national economy is very significant. UHV technology and equipment research and development has been included in the "national long-term science and technology development plan".
一、特高压输电技术的优越性
The superiority of UHV transmission technology
与500千伏输电技术相比，特高压输电技术在提高输送容量、节约土地资源、减少输电损耗和节省工程投资等方面具有明显优势。
Compared with 500 thousand volt power transmission technology, UHV transmission technology has obvious advantages in improving transmission capacity, saving land resources, reducing transmission losses and saving engineering investment.
1.输送容量大
1 large transport capacity
Transfer power of 1 million volt high-voltage AC transmission line is 500 thousand volts EHV AC transmission 4.5 ~ 5 times, in the design of the same type of tower under the condition that the transmission capacity of the unit corridor width is about 2.5 times as much as 500 thousand volts EHV AC transmission. 800 thousand volts high voltage DC transmission line unit corridor width of transmission capacity of about 500 thousand volts DC transmission of 1.3 times.
2.节约土地资源
2 saving land resources
Xiluodu, Xiangjiaba project, Wudongde, Baihetan Hydropower Station by + 800 thousand volt DC compared with the + 600 thousand volt level DC transmission line can be reduced to 6 from 10 back to back. Overall, 1 million volts and 500 thousand volts AC UHV AC transmission can save about 2/3 of land resources, compared to + 800 thousand volts high voltage DC transmission and + 500 thousand volt DC transmission can save about 1/4 of land resources.
3.输电损耗低
3 low transmission loss
FDEH风能电缆与500千伏输电相比，特高压输电线路损耗大大降低。FDEH风能电缆，1000千伏特高压交流线路损耗是500千伏交流线路的1/16～1/4;±800千伏特高压直流线路损耗是±500千伏直流线路的39%。
Compared with the 500 thousand volt transmission, the loss of UHV transmission line is greatly reduced. 1 million volts high voltage AC line loss is 500 thousand volts AC line 1/16 ~ 1/4; + 800 thousand volts high voltage DC transmission line loss is + 500 thousand volts DC line 39%.
4.工程造价省
4 engineering cost saving
采用特高压输电技术可以节省大量导线和铁塔材料，以相对较少的投入达到同等的建设规模，从而降低建设成本。在输送容量相同的条件下，1000千伏特高压交流输电与500千伏交流输电相比，节省导线材料约一半，节省铁塔用材约2/3。1000千伏特高压交流输电方案的单位输送容量综合造价约为500千伏交流输电的3/4。±800千伏特高压直流输电方案的单位输送容量投资约为±500千伏直流输电的72%。
The use of extra high voltage power transmission technology can save a lot of wire and tower materials, with relatively less input to achieve the same construction scale, thereby reducing the cost of construction. Under the same transmission capacity, the 1 million volts high-voltage AC transmission and 500 thousand volts AC transmission compared to save about half of the wire material, save the tower material about 2/3. 1 million volts high voltage AC transmission scheme of the unit transmission capacity comprehensive cost of about 500 thousand volts AC transmission 3/4. The transmission capacity of the unit of the 800 thousand volts high voltage direct current transmission scheme is approximay 500 thousand of the 72%.
二、特高压输电技术研究
Two, UHV transmission technology research
特高压输电通过采用更高的电压等级实现输电
High voltage transmission through the use of a higher voltage level
