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3 phase transmission line mutual coupling

  1. Nov 28, 2014 #1
    Hi, if I simulate a three phase transmission line operating with a fault across two of the phases, would the mutual coupling have any effect on the current through each of the lines, as I have calculated the fault current values using symmetrical component analysis and the values are consistently slightly higher than those obtained from physical simulation testing using a three phase transmission line that I have constructed using an inductor and resistor in series per phase?
  2. jcsd
  3. Nov 28, 2014 #2
    The inductors values represent mutual inductive coupling between two lines in this case. Maybe you used values for line to ground return fault (which are close but identical)
  4. Nov 28, 2014 #3
    What I have done is used a 3 phase inductive load bank to simulate a transmission line. I have then (using the known inductance and resistance values from this load bank), used symmetrical component analysis to calculate the theoretical currents through the system and these are all about 0.1A above the values measured from testing of the physical system. Because the calculations will not take the mutual coupling values between the phases into account, but the mutual coupling will still affect the measured results, would this cause the measured values to be slightly lower than the calculated ones?
  5. Nov 28, 2014 #4
    Inductivities (and hence reactances) of the conductors of a transmission line increase total reactance seen by source powering the fault. Therefore, the fault current will be smaller far away from the source.
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