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Homework Help: [Power system] The choice of transmission line

  1. Oct 13, 2012 #1

    I'm kind of struggling on finding information regarding the transfer of 1000MW to a load located 500km away.

    As far as 400kV transmission line is considered I can't find a design similar to these therefore would anyone be able if the following would be correct:

    (using ERACS)
    - L6 pylons
    - 4x400mm2 ACSR 75*
    - Double circuit
    - Ignoring magnetic effects etc. (only power flow study)

    Initial test to transfer 1000MW with double circuit has showed an error because of unacceptable voltage drop of 0.36pu, where acceptable range is set default in ERACS to 0.2.

    Therefore can I put another conductor in parallel to each side ? This will make a set of 8x400mm2 conductors in each side.

    The idea is that the report doesn't have to include much details regarding the choice but I still would like to refer to some real-life experiences/regulations.

  2. jcsd
  3. Oct 14, 2012 #2


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    Science Advisor
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    Gold Member

    I am unfamiliar with your conductor size and code reference. You may be talking a 2-pole DC line. But generally speaking, to reduce the voltage drop to acceptable levels, which is largely due to the wire resistance at the calculated current, you are correct that you can add a second conductor per pole , or use a larger conductor, to reduce the drop and line losses. Many high voltage transmission lines use 2 or 3 or more conductors per pole ( or per phase if 3-phase AC transmission). I'm not an electrical type, though, so I can't help much with calcs.
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