Comparison of economical efficiency between UHV transmission and EHV transmission
Compared with the economical efficiency of UHV and UHV transmission, the cost of transmission is generally used to compare the transmission cost used to transmit the same power and the same distance between two voltage levels. There are 2 ways to compare:
One is to compare their one-time investment costs by the same reliability index;
The other is to compare their life cycle costs.
The basic data required for these two comparison methods are:
Statistical equipment prices and construction costs for the two voltage grade transmission projects. For the cost comparison of the UHV transmission and EHV transmission project planning and design, the equipment price and its construction cost can adopt the statistical average price or price index.
Both kinds of comparison methods need to be calculated by reliability analysis. Through analysis and calculation, the expected reliability index of transmission engineering is proposed. Economic comparison using the life cycle cost method also requires statistical economic loss data that interrupts transmission.
The transmission capacity of a 1100 kV extra-high voltage power line
can reach more than 4 times the transmission capacity of a 500 kV conventional transmission line. That is, the transmission capacity of a 4-5 500 kV transmission line is equivalent to the transmission capacity of a 1100 kV transmission line. . Obviously, in terms of operation and maintenance of lines and substations, the cost of UHV transmission will be much lower than that of ultra-high voltage transmission. The loss of power and power of the line occupies a considerable proportion in terms of operating costs. The power loss of the 1100 kV line is approximately 1/16 that of a 500 kV line when delivering the same power. Therefore, UHV transmission has a stronger competitive advantage in terms of operating costs.