Re: AC OPF Convergence Issue
Thank you for the guidance! The main issue was with the values I assumed for Vm. My case is converging now. sincerely, Aakanksha *Dubey* On Tue, Mar 13, 2018 at 9:52 AM, Ray Zimmerman <r...@cornell.edu> wrote: > Making Vm = 1 means that the voltage is equal to its nominal value > specified in the BASE_KV column of the bus matrix. > > Regarding relaxing line limits, first this is the one case where setting > them to zero is interpreted as completely unconstrained. That is a > reasonable thing to try in the process of trying to get a convergent case. > The question of what sort of violations of the original limits are > acceptable depends of course on the particular system and scenario you are > trying to analyze/optimize. > > Ray > > > > On Mar 7, 2018, at 10:21 PM, Aakanksha Dubey <aad...@lehigh.edu> wrote: > > Thank You, Mirish and Shri for the guidance. > > Shri, the model is converging now. I understand that Vmax and Vmin limits > should have been more relaxed. I have a couple of quick follow-up > questions: > >- I had set the voltage magnitudes on per unit basis since the network >voltages range from 69kV to 500kV. By now making Vm=1, wouldn't all >voltages be set equal to 500kV? >- Also, while relaxing line limits, what is the maximum acceptable >percentage I should be increasing those values to? > > > sincerely, > Aakanksha *Dubey* > > > On Wed, Mar 7, 2018 at 7:25 PM, Abhyankar, Shrirang G. <abhy...@anl.gov> > wrote: > >> The voltage magnitudes in MATPOWER data files, (bus(:,VM)), are given in >> per unit and are generally close to 1.0. You have very low voltages for >> many of the buses. Similarly, the VMAX and VMIN values are also in per unit >> and generally they are 1.0 and 0.95, respectively. The following code >> results in convergent OPF. >> >> >> >> mpc = loadcase(‘Transmission3’); >> >> define_constants; >> >> mpc.bus(:,VM) = 1.0; >> >> mpc.bus(:,VA) = 0.0; >> >> mpc.bus(:,VMAX) = 1.1; >> >> mpc.bus(:,VMIN) = 0.9; >> >> runopf(mpc); >> >> >> >> Also, note that when relaxing the limits set them to large values, not >> zeros. >> >> >> >> Thanks, >> >> Shri >> >> Ph: (630) 252 0219 <(630)%20252-0219> >> >> www.mcs.anl.gov/~abhyshr >> >> *From: *<bounce-122357558-73493...@list.cornell.edu> on behalf of >> Aakanksha Dubey <aad...@lehigh.edu> >> *Reply-To: *MATPOWER discussion forum <matpowe...@list.cornell.edu> >> *Date: *Wednesday, March 7, 2018 at 4:23 PM >> *To: *"MATPOWER-L@cornell.edu" <MATPOWER-L@cornell.edu> >> *Subject: *AC OPF Convergence Issue >> >> >> >> Hi All, >> >> >> >> I am developing a model for transmission grid at Lehigh Valley. My model >> seems to converge for DC OPF but is unable to converge for AC. I have tried >> the following to make it converge but nothing works: >> >> >> >> · Relaxed Vmax, Vmix, BR_R, Rate_A,Rate_B,Rate_C >> >> · Checked the tap ratio, Qmax, Qmin,Pmax,Pmin >> >> · Tried to change the OPF options by using opf.init_from_mpc >> >> · Using mpoption I tried to change the solver to IPOPT& MINOPF >> but MATLAB keeps giving me an error that I need to download it. After >> downloading and connecting the path to MATLAB it gives me the same error. >> >> I have attached my casefiles to this email. Please let me know if anyone >> can find an issue with the model. >> >> >> >> Thank you! >> >> >> >> Aakanksha >> >> >> > > >
Re: AC OPF Convergence Issue
Thank You, Mirish and Shri for the guidance. Shri, the model is converging now. I understand that Vmax and Vmin limits should have been more relaxed. I have a couple of quick follow-up questions: - I had set the voltage magnitudes on per unit basis since the network voltages range from 69kV to 500kV. By now making Vm=1, wouldn't all voltages be set equal to 500kV? - Also, while relaxing line limits, what is the maximum acceptable percentage I should be increasing those values to? sincerely, Aakanksha *Dubey* On Wed, Mar 7, 2018 at 7:25 PM, Abhyankar, Shrirang G. <abhy...@anl.gov> wrote: > The voltage magnitudes in MATPOWER data files, (bus(:,VM)), are given in > per unit and are generally close to 1.0. You have very low voltages for > many of the buses. Similarly, the VMAX and VMIN values are also in per unit > and generally they are 1.0 and 0.95, respectively. The following code > results in convergent OPF. > > > > mpc = loadcase(‘Transmission3’); > > define_constants; > > mpc.bus(:,VM) = 1.0; > > mpc.bus(:,VA) = 0.0; > > mpc.bus(:,VMAX) = 1.1; > > mpc.bus(:,VMIN) = 0.9; > > runopf(mpc); > > > > Also, note that when relaxing the limits set them to large values, not > zeros. > > > > Thanks, > > Shri > > Ph: (630) 252 0219 <(630)%20252-0219> > > www.mcs.anl.gov/~abhyshr > > *From: *<bounce-122357558-73493...@list.cornell.edu> on behalf of > Aakanksha Dubey <aad...@lehigh.edu> > *Reply-To: *MATPOWER discussion forum <matpowe...@list.cornell.edu> > *Date: *Wednesday, March 7, 2018 at 4:23 PM > *To: *"MATPOWER-L@cornell.edu" <MATPOWER-L@cornell.edu> > *Subject: *AC OPF Convergence Issue > > > > Hi All, > > > > I am developing a model for transmission grid at Lehigh Valley. My model > seems to converge for DC OPF but is unable to converge for AC. I have tried > the following to make it converge but nothing works: > > > > · Relaxed Vmax, Vmix, BR_R, Rate_A,Rate_B,Rate_C > > · Checked the tap ratio, Qmax, Qmin,Pmax,Pmin > > · Tried to change the OPF options by using opf.init_from_mpc > > · Using mpoption I tried to change the solver to IPOPT& MINOPF > but MATLAB keeps giving me an error that I need to download it. After > downloading and connecting the path to MATLAB it gives me the same error. > > I have attached my casefiles to this email. Please let me know if anyone > can find an issue with the model. > > > > Thank you! > > > > Aakanksha > > >
AC OPF Convergence Issue
Hi All,
I am developing a model for transmission grid at Lehigh Valley. My model
seems to converge for DC OPF but is unable to converge for AC. I have tried
the following to make it converge but nothing works:
- Relaxed Vmax, Vmix, BR_R, Rate_A,Rate_B,Rate_C
- Checked the tap ratio, Qmax, Qmin,Pmax,Pmin
- Tried to change the OPF options by using opf.init_from_mpc
- Using mpoption I tried to change the solver to IPOPT& MINOPF but
MATLAB keeps giving me an error that I need to download it. After
downloading and connecting the path to MATLAB it gives me the same error.
I have attached my casefiles to this email. Please let me know if anyone
can find an issue with the model.
Thank you!
Aakanksha
mpc2 = loadcase('Transmission3');
define_constants;
%opf_ignore_ang_lim;
%load2disp(mpc2);
mpc2 = scale_load(1, mpc2);
mpc2.branch(:, [BR_R, RATE_A, RATE_B, RATE_C]) = 0;
%mpopt = mpoption('pf.alg', 'FDXB', 'pf.tol', 1e-4);
mpopt=mpoption('opf.ac.solver','DEFAULT','verbose',3);
r2 = runopf(mpc2,mpopt);
%ybuss=makeYbus(mpc2);
function mpc = Transmission3
%BUS Connections for 500KV, 230KV, 138KV, 115KV and 69KV line
mpc.version = '2';
%% Power Flow Data -%%
%System MVA base
mpc.baseMVA = 1725;
%bus data
% bus_i bus_type Pd Qd Gs Bs area Vm Va baseKV zone Vmax Vmin
mpc.bus = [
1 1 0 0 0 0 1 1 90
500 1 1.060.94;
2 3 0 0 0 0 1 1 90
500 1 1.060.94;
3 1 0 0 0 0 1 1 90
500 1 1.060.94;
4 1 0 0 0 0 1 0.4690
500 1 0.4876 0.4324;
5 1 0 0 0 0 1 0.4690
500 1 0.4876 0.4324;
6 1 0 0 0 0 1 0.4690
500 1 0.4876 0.4324;
7 1 0 0 0 0 1 0.4690
500 1 0.4876 0.4324;
8 1 0 0 0 0 1 0.276 90
500 1 0.29256 0.2594;
9 2 0 0 0 0 1 1 90
500 1 1.060.94;
10 2 0 0 0 0 1 1 90
500 1 1.060.94;
11 2 0 0 0 0 1 1 90
500 1 1.060.94;
12 2 0 0 0 0 1 1 90
500 1 1.060.94;
13 2 0 0 0 0 1 1 90
500 1 1.060.94;
14 2 0 0 0 0 1 1 90
500 1 1.060.94;
15 2 0 0 0 0 1 1 90
500 1 1.060.94;
16 2 0 0 0 0 1 1 90
500 1 1.060.94;
17 2 0 0 0 0 1 1 90
500 1 1.060.94;
18 2 0 0 0 0 1 1 90
500 1 1.060.94;
19 2 0 0 0 0 1 0.4690
500 1 0.4876 0.4324;
20 2 0 0 0 0 1 0.4690
500 1 0.4876 0.4324;
21 2 0 0 0 0 1 0.4690
500 1 0.4876 0.4324;
22 2 0 0 0 0 1 0.4690
500 1 0.4876 0.4324;
23 2 0 0 0 0 1 0.4690
500 1 0.4876 0.4324;
24 2 20.615.40 0 1 0.276 90
500 1 0.29256 0.2594;
25 2 20.615.40 0 1 0.276 90
500 1 0.29256 0.2594;
26 2 20.615.40 0 1 0.276 90
500 1 0.29256 0.2594;
27 2 20.615.40 0 1 0.276 90
500 1 0.29256 0.2594;
28 2 20.615.40 0 1 0.276 90
500 1 0.29256 0.2594;
29 2 20.615.40 0 1 0.276 90
500 1 0.29256 0.2594;
30 2 20.615.40 0 1 0.276 90
500 1 0.29256 0.2594;
31 2 20.615.40 0 1 0.276 90
500 1 0.29256 0.2594;
32 2 20.615.40 0 1 0.276 90
500 1 0.29256 0.2594;
33 2 20.615.40 0 1 0.276 90
500 1
