I don't know whether you set the bus where your cap bank is located a PQ bus or a PV bus. From the unchanged results I could guess that it's a PQ bus. Keep in mind that when you do a simple load flow, voltage limits and generator output limits are not considered. In your case, Pg and Qg of the dummy generator are set to to zero. This leads to the output of the generator being zero when you do the load flow (because it is a PQ bus so the values of Pg and Qg are used). So the results won't change.
Set the bus to a PV one. Then in load flow the capacitor will take effect.Or simply do an OPF and all the limits will be considered. Notice that in this way of modeling the cap banks, the capacity is adjusted continuously. Sorry, not a native speaker :) Hope this helps. On Fri, Apr 20, 2012 at 1:33 PM, Sam Hazim <[email protected]> wrote: > > > > > Hi everyone, > I am new to Matpower, i have some few questions about power flow . > > I have been given in my assignment some possible locations for capacitor > banks to be placed on the system. > > 1: I want to make sure, to include any cap bank on any bus, is it correct > be placed within generator data matrix and set Pg,Qg,Qmin =0, vg=1, Qgmax= > 300 (value given in my assignment). > 2: from my knowledge, we use cap banks order to minimize losses or support > voltage.i tried to connect them to the high voltage bus or to the main > transform, or other locations and then runpf. the answer doesn't change at > all ( Why is that). i have got min voltage at one bus is about 0.831 and it > should be between a recommend range 0.95 to 1.05. > > I have included the case file for two modified cases.and runpf , the results > are the same for both of them. > > Please, any suggestions will be very helpful for me to tackle this problem. > > Raad > > function > mpc = case18 > %%----- Power Flow Data -----%% > %% system MVA base > mpc.baseMVA = 500; > %% bus data > % bus_i type Pd Qd Gs Bs area Vm Va baseKV zone Vmax Vmin > mpc.bus = [ > 1 3 0 0 0 0 1 1 0 220 1 1.05 0.95; > 2 1 0 0 0 0 1 1 0 220 1 1.05 0.95; > 3 2 0 0 0 0 1 1 0 220 1 1.05 0.95; > 4 1 0 0 0 0 1 1 0 220 1 1.05 0.95; > 5 2 0 0 0 0 1 1 0 220 1 1.05 0.95; > 6 1 200 50 0 0 1 1 0 220 1 1.05 0.95; > 7 1 450 115 0 0 1 1 0 220 1 1.05 0.95; > 8 2 0 0 0 0 1 1 0 220 1 1.05 0.95; > 9 1 0 0 0 0 1 1 0 220 1 1.05 0.95; > 10 1 0 0 0 0 1 1 0 220 1 1.05 0.95; > 11 1 0 0 0 0 1 1 0 220 1 1.05 0.95; > 12 1 200 50 0 0 1 1 0 110 1 1.05 0.95; > 13 1 150 40 0 0 2 1 0 110 1 1.05 0.95; > 14 1 250 65 0 0 2 1 0 110 1 1.05 0.95; > 15 1 750 190 0 0 2 1 0 110 1 1.05 0.95; > 16 2 0 0 0 0 2 1 0 33 1 1.05 0.95; > 17 1 0 0 0 0 2 1 0 220 1 1.05 0.95; > 18 2 0 0 0 0 2 1 0 110 1 1.05 0.95; > ]; > %% generator data > % bus Pg Qg Qmax Qmin Vg mBase status Pmax Pmin Pc1 Pc2 Qc1min Qc1max Qc2min > Qc2max ramp_agc ramp_10 ramp_30 ramp_q apf > mpc.gen = [ > 1 500 0 750 -200 1.05 500 1 1250 0 0 0 0 0 0 0 0 0 0 0 0; > 3 450 0 50 -150 1.05 500 1 500 0 0 0 0 0 0 0 0 0 0 0 0; > 5 550 0 200 -150 1.028 500 1 600 0 0 0 0 0 0 0 0 0 0 0 0; > 8 50 0 65 -200 0.95 500 1 120 0 0 0 0 0 0 0 0 0 0 0 0; > 16 400 0 300 -40 1.022 500 1 500 0 0 0 0 0 0 0 0 0 0 0 0; > 18 250 0 220 -100 0.99 500 1 350 0 0 0 0 0 0 0 0 0 0 0 0; > 9 0 0 300 0 1 500 1 0 0 0 0 0 0 0 0 0 0 0 0 0; > 12 0 0 300 0 1 500 1 0 0 0 0 0 0 0 0 0 0 0 0 0; > 13 0 0 300 0 1 500 1 0 0 0 0 0 0 0 0 0 0 0 0 0; > 14 0 0 300 0 1 500 1 0 0 0 0 0 0 0 0 0 0 0 0 0; > 15 0 0 300 0 1 500 1 0 0 0 0 0 0 0 0 0 0 0 0 0; > ]; > %% branch data > % fbus tbus r x b rateA rateB rateC ratio angle status > mpc.branch = [ > 1 3 0.0712 0.3595 0.0982 524 0 0 0 0 1; > 4 5 0.0978 0.5855 0.0773 455 0 0 0 0 1; > 4 6 0.023 0.1615 0.01 671 0 0 0 0 1; > 4 7 0.0201 0.1548 0.0395 766 0 0 0 0 1; > 4 2 0.0112 0.1136 0.0071 766 0 0 0 0 1; > 7 2 0.0112 0.1136 0.0071 766 0 0 0 0 1; > 7 9 0.01 0.0954 0.0058 915 0 0 0 0 1; > 1 6 0.042 0.2715 0.017 493 0 0 0 0 1; > 1 7 0.088 0.5675 0.0356 323 0 0 0 0 1; > 1 17 0.0444 0.2104 0.0247 323 0 0 0 0 1; > 7 17 0.0444 0.2104 0.0247 323 0 0 0 0 1; > 7 18 0.0000 0.08 0.00 2000 0 0 1 0 1; > 7 8 0.002 0.0175 0.0011 915 0 0 0 0 1; > 7 15 0.0000 0.05 0.00 2000 0 0 1 0 1; > 8 9 0.009 0.0775 0.0047 915 0 0 0 0 1; > 9 10 0.0095 0.078 0.005 827 0 0 0 0 1; > 9 11 0.079 0.4815 0.0191 408 0 0 0 0 1; > 9 14 0.00 0.15 0.00 2000 0 0 1 0 1; > 10 11 0.044 0.3585 0.0233 456 0 0 0 0 1; > 10 12 0.0000 0.15 0.00 2000 0 0 1 0 1; > 11 13 0.00000 0.30 0.00 2000 0 0 1 0 1; > 4 16 0.00 0.131 0.00 2000 0 0 1 0 1; > 3 5 0.036 0.2396 0.0667 870 0 0 0 0 1; > ]; > %%----- OPF Data -----%% > %% generator cost data > % 1 startup shutdown n x1 y1 ... xn yn > % 2 startup shutdown n c(n-1) ... c0 > mpc.gencost = [ > 2 0 0 3 0.039 20 0; > 2 0 0 3 0.029 20 0; > 2 0 0 3 0.031 20 0; > 2 0 0 3 0.12 20 0; > 2 0 0 3 0.25 20 0; > 2 0 0 3 0.1 20 0; > 2 0.01 0 3 0.01 40 0; > 2 0.01 0 3 0.01 40 0; > 2 0.01 0 3 0.01 40 0; > 2 0.01 0 3 0.01 40 0; > 2 0.01 0 3 0.01 40 0; > ]; > > This is the modifed case > > function > mpc = case18 > %%----- Power Flow Data -----%% > %% system MVA base > mpc.baseMVA = 500; > %% bus data > % bus_i type Pd Qd Gs Bs area Vm Va baseKV zone Vmax Vmin > mpc.bus = [ > 1 3 0 0 0 0 1 1 0 220 1 1.05 0.95; > 2 1 0 0 0 0 1 1 0 220 1 1.05 0.95; > 3 2 0 0 0 0 1 1 0 220 1 1.05 0.95; > 4 1 0 0 0 0 1 1 0 220 1 1.05 0.95; > 5 2 0 0 0 0 1 1 0 220 1 1.05 0.95; > 6 1 200 50 0 0 1 1 0 220 1 1.05 0.95; > 7 1 450 115 0 0 1 1 0 220 1 1.05 0.95; > 8 2 0 0 0 0 1 1 0 220 1 1.05 0.95; > 9 1 0 0 0 0 1 1 0 220 1 1.05 0.95; > 10 1 0 0 0 0 1 1 0 220 1 1.05 0.95; > 11 1 0 0 0 0 1 1 0 220 1 1.05 0.95; > 12 1 200 50 0 0 1 1 0 110 1 1.05 0.95; > 13 1 150 40 0 0 2 1 0 110 1 1.05 0.95; > 14 1 250 65 0 0 2 1 0 110 1 1.05 0.95; > 15 1 750 190 0 0 2 1 0 110 1 1.05 0.95; > 16 2 0 0 0 0 2 1 0 33 1 1.05 0.95; > 17 1 0 0 0 0 2 1 0 220 1 1.05 0.95; > 18 2 0 0 0 0 2 1 0 110 1 1.05 0.95; > ]; > %% generator data > % bus Pg Qg Qmax Qmin Vg mBase status Pmax Pmin Pc1 Pc2 Qc1min Qc1max Qc2min > Qc2max ramp_agc ramp_10 ramp_30 ramp_q apf > mpc.gen = [ > 1 500 0 750 -200 1.05 500 1 1250 0 0 0 0 0 0 0 0 0 0 0 0; > 3 450 0 50 -150 1.05 500 1 500 0 0 0 0 0 0 0 0 0 0 0 0; > 5 550 0 200 -150 1.028 500 1 600 0 0 0 0 0 0 0 0 0 0 0 0; > 8 50 0 65 -200 0.95 500 1 120 0 0 0 0 0 0 0 0 0 0 0 0; > 16 400 0 600 -40 1.022 500 1 500 0 0 0 0 0 0 0 0 0 0 0 0; > 18 250 0 520 -100 0.99 500 1 350 0 0 0 0 0 0 0 0 0 0 0 0; > 12 0 0 300 0 1 500 1 0 0 0 0 0 0 0 0 0 0 0 0 0; > 13 0 0 300 0 1 500 1 0 0 0 0 0 0 0 0 0 0 0 0 0; > 14 0 0 300 0 1 500 1 0 0 0 0 0 0 0 0 0 0 0 0 0; > 15 0 0 300 0 1 500 1 0 0 0 0 0 0 0 0 0 0 0 0 0; > ]; > %% branch data > % fbus tbus r x b rateA rateB rateC ratio angle status > mpc.branch = [ > 1 3 0.0712 0.3595 0.0982 524 0 0 0 0 1; > 4 5 0.0978 0.5855 0.0773 455 0 0 0 0 1; > 4 6 0.023 0.1615 0.01 671 0 0 0 0 1; > 4 7 0.0201 0.1548 0.0395 766 0 0 0 0 1; > 4 2 0.0112 0.1136 0.0071 766 0 0 0 0 1; > 7 2 0.0112 0.1136 0.0071 766 0 0 0 0 1; > 7 9 0.01 0.0954 0.0058 915 0 0 0 0 1; > 1 6 0.042 0.2715 0.017 493 0 0 0 0 1; > 1 7 0.088 0.5675 0.0356 323 0 0 0 0 1; > 1 17 0.0444 0.2104 0.0247 323 0 0 0 0 1; > 7 17 0.0444 0.2104 0.0247 323 0 0 0 0 1; > 7 18 0.0000 0.08 0.00 2000 0 0 1 0 1; > 7 8 0.002 0.0175 0.0011 915 0 0 0 0 1; > 7 15 0.0000 0.05 0.00 2000 0 0 1 0 1; > 8 9 0.009 0.0775 0.0047 915 0 0 0 0 1; > 9 10 0.0095 0.078 0.005 827 0 0 0 0 1; > 9 11 0.079 0.4815 0.0191 408 0 0 0 0 1; > 9 14 0.00 0.15 0.00 2000 0 0 1 0 1; > 10 11 0.044 0.3585 0.0233 456 0 0 0 0 1; > 10 12 0.0000 0.15 0.00 2000 0 0 1 0 1; > 11 13 0.00000 0.30 0.00 2000 0 0 1 0 1; > 4 16 0.00 0.131 0.00 2000 0 0 1 0 1; > 3 5 0.036 0.2396 0.0667 870 0 0 0 0 1; > ]; > %%----- OPF Data -----%% > %% generator cost data > % 1 startup shutdown n x1 y1 ... xn yn > % 2 startup shutdown n c(n-1) ... c0 > mpc.gencost = [ > 2 0 0 3 0.039 20 0; > 2 0 0 3 0.029 20 0; > 2 0 0 3 0.031 20 0; > 2 0 0 3 0.12 20 0; > 2 0 0 3 0.25 20 0; > 2 0 0 3 0.1 20 0; > 2 0.01 0 3 0.01 40 0; > 2 0.01 0 3 0.01 40 0; > 2 0.01 0 3 0.01 40 0; > 2 0.01 0 3 0.01 40 0; > ]; > > > Converged in 0.01 seconds > ================================================================================ > | System > Summary | > ================================================================================ > How many? How much? P (MW) Q (MVAr) > --------------------- ------------------- ------------- > ----------------- > Buses 18 Total Gen Capacity 3320.0 -840.0 to > 3085.0 > Generators 11 On-line Capacity 3320.0 -840.0 to > 3085.0 > Committed Gens 11 Generation (actual) 2156.4 1435.9 > Loads 6 Load 2000.0 510.0 > Fixed 6 Fixed 2000.0 510.0 > Dispatchable 0 Dispatchable -0.0 of -0.0 -0.0 > Shunts 0 Shunt (inj) -0.0 0.0 > Branches 23 Losses (I^2 * Z) 156.39 1158.17 > Transformers 6 Branch Charging (inj) - 232.3 > Inter-ties 7 Total Inter-tie Flow 2571.5 945.4 > Areas 2 > Minimum Maximum > ------------------------- -------------------------------- > Voltage Magnitude 0.831 p.u. @ bus 13 1.050 p.u. @ bus 1 > Voltage Angle -35.25 deg @ bus 13 23.07 deg @ bus 5 > P Losses (I^2*R) - 41.38 MW @ line 4-5 > Q Losses (I^2*X) - 247.71 MVAr @ line 4-5 > ================================================================================ > | Bus > Data | > ================================================================================ > Bus Voltage Generation Load > # Mag(pu) Ang(deg) P (MW) Q (MVAr) P (MW) Q (MVAr) > ----- ------- -------- -------- -------- -------- -------- > 1 1.050 0.000* 456.39 467.50 - - > 2 0.951 -13.498 - - - - > 3 1.050 20.596 450.00 9.55 - - > 4 0.966 -8.517 - - - - > 5 1.028 23.071 550.00 6.34 - - > 6 0.979 -7.475 - - 200.00 50.00 > 7 0.942 -18.601 - - 450.00 115.00 > 8 0.950 -19.251 50.00 412.70 - - > 9 0.918 -22.228 0.00 -0.00 - - > 10 0.895 -24.961 - - - - > 11 0.866 -28.061 - - - - > 12 0.875 -29.353 0.00 0.00 200.00 50.00 > 13 0.831 -35.246 0.00 0.00 150.00 40.00 > 14 0.892 -27.487 0.00 -0.00 250.00 65.00 > 15 0.918 -23.576 0.00 -0.00 750.00 190.00 > 16 1.022 -2.425 400.00 238.60 - - > 17 0.986 -8.824 - - - - > 18 0.990 -16.144 250.00 301.23 - - > -------- -------- -------- -------- > Total: 2156.39 1435.91 2000.00 510.00 > ================================================================================ > | 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 3 -500.37 170.04 537.73 -35.56 37.356 > 188.62 > 2 4 5 -420.13 126.90 461.51 82.35 41.377 > 247.71 > 3 4 6 -57.23 -30.30 57.43 26.97 0.200 > 1.40 > 4 4 7 521.76 43.70 -509.92 29.51 11.841 > 91.20 > 5 4 2 355.61 43.89 -352.52 -15.87 3.083 > 31.27 > 6 7 2 -349.44 12.25 352.52 15.87 3.086 > 31.30 > 7 7 9 297.02 98.30 -294.81 -79.72 2.211 > 21.09 > 8 1 6 263.72 108.81 -257.43 -76.97 6.280 > 40.60 > 9 1 7 293.50 89.95 -278.16 -8.73 15.341 > 98.93 > 10 1 17 399.54 98.69 -385.78 -46.32 13.754 > 65.18 > 11 7 17 -371.93 7.85 385.78 46.32 13.855 > 65.66 > 12 7 18 -250.00 -276.21 250.00 301.23 -0.000 > 25.02 > 13 7 8 262.43 -239.01 -261.86 243.48 0.567 > 4.96 > 14 7 15 750.00 261.04 -750.00 -190.00 -0.000 > 71.04 > 15 8 9 311.86 169.22 -309.34 -149.58 2.518 > 21.68 > 16 9 10 263.98 104.83 -262.15 -91.90 1.826 > 14.99 > 17 9 11 90.17 34.30 -88.37 -30.92 1.802 > 10.98 > 18 9 14 250.00 90.17 -250.00 -65.00 -0.000 > 25.17 > 19 10 11 62.15 25.26 -61.63 -30.04 0.523 > 4.26 > 20 10 12 200.00 66.64 -200.00 -50.00 -0.000 > 16.64 > 21 11 13 150.00 60.96 -150.00 -40.00 -0.000 > 20.96 > 22 4 16 -400.00 -184.18 400.00 238.60 -0.000 > 54.41 > 23 3 5 -87.73 45.10 88.49 -76.01 0.766 > 5.10 > -------- > -------- > Total: 156.386 > 1158.17 >>> > >
