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
>
>
>

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