Current waveform difference before and after distributed parameters line

Hello everyone, I hope everyone is doing well, i am trying to simulate the faulted waveforms in a transmission line, for the receiving end i can place the 3-phase measurment block either before or after the distibuted parameters line block, in both cases the voltage is the same but the current wavform is different, I would be very grateful if anyone can tell me which is the correct placement fro the phase measurement block if i am simulating waveforms on the transmission line itself and why is it so.

Answer 1

[TED MOSBY]

Hi Abdul,

If you are simulating on the transmission line itself, it is correct to use the 3-phase measurement block on the left side of the distributed parameters line block as it will show exactly what flows into the physical conductors. Now there can be several factors which can explain the difference in your current waveforms of both left and right side :

Transformer scaling effect: the sensor on the left side sits on the low voltage side of the step up transformer, thus the current on the left side is multplied by a turns ratio hence the jump, this is a major factor in the difference.

Line charging capacitance: the current sent into the distributed parameters block will include the load current plus the sum of the charging current along the length of the transformer(it has capacitors connected to the ground at every few cms, thus amount of current leaves the conductor and goes to the ground) hence the current on left side is seen more than the right side.

Hope this helps!

[Abdul]

Thank you very much for your answer, Ted (I havent watched the show unfortunately) I really appreciate your answer and yes I will be using the left side of the distributed parameters block. I did not understand it very well the first time I read it, but now I have a solid lead to go off of, thank you very much for taking time out of your day to answer this.