The flows printed in the output are the injections from the bus into the corresponding end of the branch. Because of reactive losses (which can be negative, due to reactive power injection from line charging), the absolute values of the reactive flows at either end of the line are not expected to be identical. And in fact, when the line charging injections are high enough, as in branch 3, you see reactive power flowing out of the line at both ends.
So, the bottom line is that I’m not sure there is a universally accepted definition for “reactive flow” in a branch. I suppose you could use the average of the flow at the two ends or something, but you have to define what you mean by the term. Ray > On Sep 26, 2017, at 1:05 PM, Mahbubur R <[email protected]> wrote: > > Hello everyone, > I have some problem understanding the direction of the reactive power flow. > How do I calculate the flow of reactive power through a single line (i.e. for > branch 1 here)? Also how to calculate the flow when signs for both of to and > from buses are negative (i.e. branch 3)? > > I know it has something to do with line susceptance, but could not exactly > figure it out. Should not the absolute value of reactive power flow from Bus > 1 to 4, and from Bus 4 to 1 should be the same? > > I will highly appreciate some clarification regarding this. > > Thanks and regards - > Mahi > > Brnch From To From Bus Injection To Bus Injection Loss (I^2 * Z) > > # Bus Bus P (MW) Q (MVAr) P (MW) Q (MVAr) P (MW) Q > (MVAr) > ----- ----- ----- -------- -------- -------- -------- -------- > -------- > 1 1 4 70.88 9.34 -70.61 -15.22 0.268 1.30 > 2 4 5 61.46 8.89 -61.22 -15.77 0.237 1.13 > 3 5 6 -28.78 -14.23 28.92 -7.72 0.140 0.69 > 4 3 6 85.00 5.80 -84.62 -11.14 0.378 1.83 > 5 6 7 55.70 18.87 -55.49 -25.82 0.218 1.04 > 6 7 8 -44.51 -9.18 44.85 -11.70 0.334 1.65 > 7 8 2 -161.62 -6.01 163.00 5.54 1.378 6.68 > 8 8 9 116.77 17.70 -115.92 -21.54 0.855 4.08 > 9 9 4 -9.08 -28.46 9.15 6.33 0.066 0.32
