hello,
Reactive power flow balance equation is as follows:
Qgeneration+Qcharging=Qload+Qloss .
(Due to presence of capacitive effect, transmission line injects reactive power
in to the system.)
so Qfrombus+Qtobus=Qloss doesn't hold.
regards
________________________________
From: z qin <zhengr...@gmail.com>
To: matpower-l <matpowe...@cornell.edu>
Sent: Mon, April 25, 2011 8:19:11 AM
Subject: Help on the reactive power flow in matpower.
Hello,
I ran runopf('case9.m') and got the result below. In some branches (1, 4 and
7), Qfrombus+Qtobus=Qloss. However for the rest branches,
Qfrombus+Qtobus=Qloss
doesn't hold. Could someone explain for me? I had thought that
Qij=|Vi|*|Vi|*Bij+|Vi|*|Vj|*(Gij*sin(theta_i-theta_j)-Bij*cos(theta_i-theta_j),
but it seems that it is wrong. Thanks a lot.
Btw, here is how I calculate Pij and Qij. Sij=Pij+1j*Qij=V_i*(I_ij^*), from
the
real part, I get Pij, which seems correct; from the imaginary part, I got Qij,
which seems wrong.
Best,
Jerry.
Branch Data |
================================================================================
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 89.80 12.94 -89.80 -9.02 0.000 3.92
2 4 5 35.22 -3.90 -35.04 -13.87 0.181 0.98
3 5 6 -54.96 -16.13 55.97 -22.18 1.010 4.40
4 3 6 94.19 -22.62 -94.19 27.28 0.000 4.66
5 6 7 38.22 -5.10 -38.07 -18.68 0.149 1.26
6 7 8 -61.93 -16.32 62.21 0.82 0.279 2.36
7 8 2 -134.32 9.32 134.32 0.05 0.000 9.36
8 8 9 72.11 -10.14 -70.72 -18.94 1.394 7.01
9 9 4 -54.28 -31.06 54.58 12.92 0.295 2.51
