Re: AC OPF Convergence Issue

[Aakanksha Dubey]

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

[Ray Zimmerman]

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 
> <mailto: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 <tel:(630)%20252-0219>
> www.mcs.anl.gov/~abhyshr <http://www.mcs.anl.gov/~abhyshr>
> From: <bounce-122357558-73493...@list.cornell.edu 
> <mailto:bounce-122357558-73493...@list.cornell.edu>> on behalf of Aakanksha 
> Dubey <aad...@lehigh.edu <mailto:aad...@lehigh.edu>>
> Reply-To: MATPOWER discussion forum <matpowe...@list.cornell.edu 
> <mailto:matpowe...@list.cornell.edu>>
> Date: Wednesday, March 7, 2018 at 4:23 PM
> To: "MATPOWER-L@cornell.edu <mailto:MATPOWER-L@cornell.edu>" 
> <MATPOWER-L@cornell.edu <mailto: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

[Abhyankar, Shrirang G.]

From: <bounce-122358024-73493...@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 9:21 PM
To: MATPOWER discussion forum <matpowe...@list.cornell.edu>
Subject: 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?
I suggest referring to a book on per unit calculation. Here’s a simple example 
that may help get your started: 
http://peguru.com/2011/06/per-unit-system-practice-problem-solved-for-easy-understanding/
· Also, while relaxing line limits, what is the maximum acceptable 
percentage I should be increasing those values to?
There is no acceptable or unacceptable percentage. The line limits are relaxed 
simply to get the OPF to converge, but this may not be realistic for a 
practical solution.

Shri

sincerely,
Aakanksha Dubey


On Wed, Mar 7, 2018 at 7:25 PM, Abhyankar, Shrirang G. 
<abhy...@anl.gov<mailto: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<tel:(630)%20252-0219>
www.mcs.anl.gov/~abhyshr<http://www.mcs.anl.gov/~abhyshr>
From: 
<bounce-122357558-73493...@list.cornell.edu<mailto:bounce-122357558-73493...@list.cornell.edu>>
 on behalf of Aakanksha Dubey <aad...@lehigh.edu<mailto:aad...@lehigh.edu>>
Reply-To: MATPOWER discussion forum 
<matpowe...@list.cornell.edu<mailto:matpowe...@list.cornell.edu>>
Date: Wednesday, March 7, 2018 at 4:23 PM
To: "MATPOWER-L@cornell.edu<mailto:MATPOWER-L@cornell.edu>" 
<MATPOWER-L@cornell.edu<mailto: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

[Aakanksha Dubey]

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

[Abhyankar, Shrirang G.]

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
www.mcs.anl.gov/~abhyshr<http://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

[Mirish Thakur]

Hi,

I would recommend you to go through these 8 steps (Incremental approach)
suggested  by Jose L. Marin. Click the link given below and follow the
steps. When I was working with the German Grid I had same problems but
these steps really worked out in my case. I hope you will get solution.
*https://www.mail-archive.com/matpower-l@cornell.edu/msg04581.html
*

Regards
Mirish




On Wed, Mar 7, 2018 at 11:23 PM, Aakanksha Dubey  wrote:

> 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

[Aakanksha Dubey]

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