Unit 2: Per unit quantity and Transmission Line


Question 3

A 40 MVA, 20 kV/400 kV, Single phase transformer has the following series impedance

Using the transformer rating as base, determine the per-unit impedance on each side of the transformer (i.e. low/high voltage side).




Provide your response in the comment section using your surname and last two digit of your matriculation number as your identity (e.g. Abacus20)



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Comments

  1. Sir are we to just write the final answer.....

    ReplyDelete
    Replies
    1. In the comment section. Use raw text eg
      Vbase= Ibase*Zbase
      ....

      Delete
    2. Please show your formula for example if Ibase=20 and Zbase=5, then
      Vbase= Ibase*Zbase
      Vbase=20*5=100V

      Delete
  2. Sir the question is not clear.You gave 2 impedance values,is it dat one is the series impedance on the primary,and the other on the secondary?Or we are just to add them up?ciz I added the impedance straight up,since it wasn't specified.Z p.u=12.8+30i(high voltage side). While p.u=0.032+0.072i(on the secondary side).Am I on the righttrack?Or do I still need to make corrections.?I used the formulae; Zbase=(vbase)²/Sbase· and z p.u=Zactual/zbase.(the value of the actual impedances are Z1 and Z2.for both high and low voltage sides).OTUNNI11

    ReplyDelete
    Replies
    1. You don't need to add them Please separate them.
      Z1 = primary impedance
      Z2= secondary impedance
      Determine the pu value separately

      Delete
  3. On the low voltage side(primary side), Zbase=10ohms,While Zp.u=0.1+j0.18.On the high voltage side(secondary),Zbase=4kohms,while p.u=0.032+j0.072.OTUNNI 11

    ReplyDelete
  4. In the question, we were asked to use the transformer ratings as our base values.so,my S-base is 40MVA,while my v-bases are 20/400 kV.Am i ryt sir?

    ReplyDelete
    Replies
    1. Sorry for the late Reply.
      Yes you are correct. I only needed to confirm you know what you're doing.
      Good effort!!!

      Delete
  5. A-base=40MVA while vbase is=20/400KV.Am

    ReplyDelete
  6. Folahan.Michael.3120 September 2019 at 11:50

    The A Base is 40MVA
    The V Base is 20per400kilovolt

    ReplyDelete
  7. Sir the question is not clear.You gave 2 impedance values,is it dat one is the series impedance on the primary,and the other on the secondary?Or we are just to add them up?ciz I added the impedance straight up,since it wasn't specified.Z p.u=12.8+30i(high voltage side). While p.u=0.032+0.072i(on the secondary side).Am I on the righttrack?Or do I still need to make corrections.?I used the formulae; Zbase=(vbase)²/Sbase· and z p.u=Zactual/zbase.(the value of the actual impedances are Z1 and Z2.for both high and low voltage sides)

    ReplyDelete
  8. Abase=40MVA
    Vbase=20/400KV

    ReplyDelete
  9. Sir.
    The A Base is 40MVA
    The V Base is 20per400kilovolt

    ReplyDelete
  10. Ugele 1059
    Sir the question is not clear.You gave 2 impedance values,is it dat one is the series impedance on the primary,and the other on the secondary?Or we are just to add them up?ciz I added the impedance straight up,since it wasn't specified.Z p.u=12.8+30i(high voltage side). While p.u=0.032+0.072i(on the secondary side).Am I on the righttrack?Or do I still need to make corrections.?I used the formulae; Zbase=(vbase)²/Sbase· and z p.u=Zactual/zbase.(the value of the actual impedances are Z1 and Z2.for both high and low voltage sides)

    ReplyDelete
  11. Ugele 1059
    Sir the question is not clear.You gave 2 impedance values,is it dat one is the series impedance on the primary,and the other on the secondary?Or we are just to add them up?ciz I added the impedance straight up,since it wasn't specified.Z p.u=12.8+30i(high voltage side). While p.u=0.032+0.072i(on the secondary side).Am I on the righttrack?Or do I still need to make corrections.?I used the formulae; Zbase=(vbase)²/Sbase· and z p.u=Zactual/zbase.(the value of the actual impedances are Z1 and Z2.for both high and low voltage sides)

    ReplyDelete

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