1. Improve the recommended capacity.

The natural power of a 1000kV uhv transmission line is close to 5 million kw, about five times that of a 500kV transmission line.It takes an uhv dc transmission of plus or minus 800kV to reach 6.4 gigawatts, 2.1 times that of plus or minus 500kV and 1.7 times that of plus or minus 620kV.

2. Limit of fluctuation of progress.

The electrical spacing of a 1000kv line is equivalent to 1/4 ~ 1/5 of a 500kv line of the same length.In other words, under the condition of transmitting the opposite power, the extremely remote transmission interval of 1000kV uhv transmission line is about 4 times that of 500kV line.The adoption of + / - 800kV dc transmission technology enables ultra-long distance transmission, and the economic transmission interval can reach 2500km or more.

3. Reduce line loss.

The resistance loss of 1000kV ac line is a quarter of that of 500kV ac line under the condition that the total cross section of the wire and the transmitting capacity are opposite, that is, the values of R and S are equal.The resistance loss of + / - 800kV dc line is 39% of + / - 500kV dc line and 60% of + / - 620kV dc line.

4. Increase project investment.

The comprehensive cost of unit recommended capacity of 1000kV ac transmission scheme is about three-quarters of that of 500kV transmission scheme.The comprehensive cost of unit recommended capacity of + / - 800kV HVDC transmission scheme is about three-quarters of that of + / - 500kV HVDC transmission scheme.

5. Save corridor area.

Ac uhv: the corridor width of the same tower double circuit and the cat head tower single circuit is identified as 75 meters and 81 meters, the unit corridor recommended to be identified as 133,000 kw/m and 62 kw/m, about three times of the same type of 500kV circuit.

Dc uhv: the line corridor of the + / -800kv and 6.4gw HVDC transmission scheme is about 76 meters, and the recommended capacity per unit corridor width is 84,000 kw/m, which is 1.29 times that of the + / -500kv and 3 kw schemes, and 1.37 times that of the + / -620kv and 3.8 kw schemes.

6. Improve the construction of power grid.

Long interval power transmission through uhv can increase the demand for installing units in the heart area of load, thus reducing the short-circuit current amplitude.The output of 10 gigawatts of power at long intervals is equivalent to 17 additional units of 600,000 gigawatts installed locally.Each 600,000-kilowatt unit adds about 1.8kA to the fragmental short-circuit current of 500 kv in the left and near area of the unit. If these units are installed in the heart area of load, the degree of short-circuit current in the external power grid will have a greater impact.

Through the ultra-high voltage power grid, the layered partition layout can be completed, which can optimize the fragmentary structure including ultra-high voltage, and basically deal with the over-standard performance of short-circuit current