[Encyclopedia of electric power] what are the benefits of building UHV?

2021-08-21 打印
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The power transmission capacity of 1 million V AC UHV transmission line is five times that of 500000 V UHV transmission line. Therefore, it is compared that EHV transmission is a provincial highway, even a national highway at most, and UHV transmission can be said to be an "electric highway".

After the rapid development in recent years, China's expressway has basically become a network extending in all directions. China's UHV transmission, the "power highway", has just completed a pilot demonstration project at the end of 2008, with a total length of 640km. Therefore, it will take a long time to build an UHV power grid, an electric highway network, and it will inevitably cost a lot of human, material and financial resources, that is, to allocate energy resources conveniently, quickly and efficiently throughout the country.

In power engineering technology, there is a term called "economic transmission distance", which refers to the most economical transmission distance of a certain voltage level transmission line, because the transmission line will also have loss when transmitting electric energy. If the line is too long and the loss is too large, it is not cost-effective economically.

The economic transmission distance of 500000 V EHV transmission line is usually 600 ~ 800 km, while the economic transmission distance of 1 million V EHV transmission line is increased due to the increase of voltage and the reduction of line loss, which can reach 1000 ~ 1500 km or even longer, so as to solve the problem of moving western energy to the Middle East.

The construction of transmission lines also needs to occupy land, which is called "line corridor" in the project. As mentioned earlier, the construction of a 1 million volt high-voltage transmission line can top five 500000 volt ultra-high-voltage transmission lines, and the land occupied by the line corridor is only equivalent to two 500000 volt transmission lines. Therefore, the construction of UHV transmission lines can occupy less land, which is particularly beneficial to the Middle East region where land resources are scarce.

Of course, UHV transmission, especially the construction of UHV power grid, has many advantages. It can firmly connect China's power grid, so that different power plants (such as thermal power plants and hydropower plants) built in different locations can support and supplement each other. In engineering, it is called "realizing mutual aid between water and fire and achieving networking benefits"; It can promote the intensive development of coal and hydraulic resources in the West and reduce the cost of power generation; It can ensure the growing power demand in the Middle East and reduce the environmental pollution caused by the construction of thermal power plants in densely populated and economically developed areas; At the same time, it can also promote the harmonious economic and social development of resource intensive and economically underdeveloped areas in the West.

Source: jintou.com