Actually, I got the constraints added and was able to modify it without
problem through Direct Specification which I was unable to do in the
beginning. Guess I was doing something wrong which I didn't realize for
quite a while.
Thank you, sir and I guess I haven't understood how the callback functions
work. I will work on understanding the existing examples before
implementing my own.
Regards
Viswanath
On Mon, Oct 16, 2017 at 1:20 PM, Ray Zimmerman <r...@cornell.edu> wrote:
> I don’t understand why you are calling toggle_myconstraints() more than
> once. When used as intended, calling toggle_myconstraints() would
> register your callback functions. Then when you run the OPF, the callback
> functions will be called at the appropriate point in the execution to
> modify the formulation (e.g. add your new constraints). You only need to
> re-run toggle_myconstraints() if you load a new MATPOWER case that you
> want to run with your constraints enabled.
>
> It seems you are still misunderstanding how the callback functions work.
> Have you understood the existing examples (e.g. toggle_reserves(),
> toggle_iflims(), etc.) before attempting to implement your own?
>
> Ray
>
>
> On Oct 13, 2017, at 11:35 AM, Viswanath Hariharan <vhari...@buffalo.edu>
> wrote:
>
> I tried getting out of the problem by assigning allow_multiple = 1 for
> add_userfcn. But I couldn't get past this error:
> Error using opt_model/add_constraints (line 87)
> Error detected on worker 4.
> @opt_model/add_constraints: linear constraint set named 'Va' already exists
>
> Could you guide me as to how I can overwrite this too?
> Thank you sir
>
> Regards
> Viswanath
>
> On Fri, Oct 13, 2017 at 11:22 AM, Viswanath Hariharan <
> vhari...@buffalo.edu> wrote:
>
>> Sir
>> So I used the toggle_myconstraints method you had suggested to add
>> Voltage angle constraints to the problem. After getting the solution, I
>> update the constraints set and call toggle_myconstraints again. But this
>> time, I get an error :
>> Caused by:
>> Error using add_userfcn (line 119)
>> add_userfcn: the function 'userfcn_myconstraints_formulation' has
>> already been added
>>
>> How do I avoid this problem? Is there a way to overwrite what's already
>> written in both add_userfcn and the linear constraints section in om (in
>> this case 'Va')?
>>
>> Regards
>> Viswanath
>>
>> On Fri, Oct 13, 2017 at 10:04 AM, Viswanath Hariharan <
>> vhari...@buffalo.edu> wrote:
>>
>>> Thank you for your help sir. I think I was doing something wrong. It
>>> works alright now.
>>>
>>> Regards
>>> Viswanath
>>>
>>> On Oct 12, 2017 10:03 AM, "Ray Zimmerman" <r...@cornell.edu> wrote:
>>>
>>>> Are you saying that your solution includes voltage angles whose
>>>> absolute value is greater than 0.26 radians or 14.9 degrees?
>>>>
>>>> Ray
>>>>
>>>>
>>>> On Oct 11, 2017, at 8:52 PM, Viswanath Hariharan <vhari...@buffalo.edu>
>>>> wrote:
>>>>
>>>> First, thank you so much for your time, Sir.
>>>> So I tried the first approach first. I want to added box constraints
>>>> for Voltage angle, -0.26 < theta < 0.26. I created the A matrix and l and
>>>> u vectors and passed it to the opf function. The solution converged and I
>>>> did get results. But the problem is that the added constraints look like
>>>> they had no effect on the result.
>>>>
>>>> I also tried the toggle_reserves() method you suggested in the previous
>>>> email of this thread where you asked me rename toggle_reserves and all the
>>>> callback functions within it and modify its contents to toggle the addition
>>>> of constraints. I did that too. results = runopf(mpc) and results.om
>>>> had 5 linear constraints added to it. But again this had no effect on the
>>>> results. I even tried changing the bounds to see if there was any
>>>> difference but there wasn't.
>>>>
>>>> What is it that I'm missing out here?
>>>>
>>>> Regards
>>>> Viswanath
>>>>
>>>>
>>>>
>>>> On Tue, Oct 10, 2017 at 9:09 AM, Ray Zimmerman <r...@cornell.edu>
>>>> wrote:
>>>>
>>>>> It appears you have fundamentally misunderstood callback functions and
>>>>> how they work. I suggest that you read carefully the entirety of sections
>>>>> 7.2–7.5 in the User’s Manual and make sure you understand the
>>>>> toggle_reserves() example used to illustrate the approach.
>>>>>
>>>>> To implement your own constraints, I would recommend copying and
>>>>> renaming toggle_reserves() to something like toggle_myconstraints().
>>>>> Then rename all of the callback functions defined in that file to e.g.
>>>>> userfcn_myconstraints_ext2int(), userfcn_myconstraints_formulation(),
>>>>> etc., and modify their contents to reflect the constraints you want to add
>>>>> (as opposed to those implemented for the zonal reserves case). The
>>>>> “formulation” callback is where you’ll be calling add_constraints().
>>>>> Then you can simply toggle your constraints on and use runopf()
>>>>> normally.
>>>>>
>>>>> mpc = loadcase('<mycase>');
>>>>> mpc = toggle_myconstraints(mpc, 'on');
>>>>> results = runopf(mpc);
>>>>>
>>>>> Hope this helps,
>>>>>
>>>>> Ray
>>>>>
>>>>>
>>>>>
>>>>> On Oct 5, 2017, at 12:18 PM, Viswanath Hariharan <vhari...@buffalo.edu>
>>>>> wrote:
>>>>>
>>>>> Sir
>>>>>
>>>>> I tried adding constraints using the callback functions method
>>>>> described in Section 7.2 but I am not sure I followed it correctly.
>>>>> mpopt = mpoption;
>>>>> om = opf_setup(mpc, mpopt);
>>>>> om = add_constraints(om, 'Vm', A1, l1, u1);
>>>>> om = add_constraints(om, 'Va', A2, l2, u2);
>>>>> mpc = get_mpc(om)
>>>>> results2 = runopf(mpc);
>>>>>
>>>>> om gets updated with 10 linear constraints (case5 is being used here).
>>>>> But mpc doesn't get updated and hence when I run this code and check and
>>>>> results.var.mu.l.Va <http://results.var.mu.l.va/>, the constraints
>>>>> aren't updated. Not only that, the mpc file isn't getting updated as well.
>>>>> I think I am making some mistake with this line : mpc = get_mpc(om)
>>>>> because
>>>>> om is fine. What am I missing here? Or should I take another approach?
>>>>> Thank you so much for your time Sir.
>>>>>
>>>>> Regards
>>>>> Viswanath Hariharan
>>>>>
>>>>> On Thu, Oct 5, 2017 at 10:27 AM, Ray Zimmerman <r...@cornell.edu>
>>>>> wrote:
>>>>>
>>>>>> You only need to use the add_constraints() function if you are using
>>>>>> Callback Functions as described in Section 7.2 as opposed to Direct
>>>>>> Specification as described in Section 7.1 of the User’s Manual
>>>>>> <http://www.pserc.cornell.edu/matpower/docs/MATPOWER-manual-6.0.pdf>.
>>>>>>
>>>>>> You convergence failure my just imply that your variable bounds are
>>>>>> tight enough that there is no feasible solution. Try relaxing the limits
>>>>>> and see if it converges.
>>>>>>
>>>>>> Vm, Pg and Qg all have limits specified directly in the bus and gen
>>>>>> matrices. Vm is bounded by the VMIN and VMAX columns in the bus matrix.
>>>>>> Pg and Qg are bounded by the PMIN, PMAX and QMIN, QMAX columns of
>>>>>> the gen matrix, respectively. Va is not normally constrained (except
>>>>>> at the reference bus), so the bus matrix doesn’t contain bounds for it.
>>>>>> In
>>>>>> that case, you have to use the standard linear constraints of equation
>>>>>> (6.25) to impose bounds.
>>>>>>
>>>>>> At a lower lever, variable bounds are defined when variables are
>>>>>> added via the add_vars() method. The Va, Vm, Pg and Qg variables are
>>>>>> added automatically (with their bounds) in opf_setup(), so you can’t
>>>>>> really modify them there. But for any variables you add later, you supply
>>>>>> the bounds when you call add_vars().
>>>>>>
>>>>>> Ray
>>>>>>
>>>>>>
>>>>>>
>>>>>> On Oct 4, 2017, at 3:52 PM, Viswanath Hariharan <vhari...@buffalo.edu>
>>>>>> wrote:
>>>>>>
>>>>>> So I do not need to use the add_constraints function? Because when I
>>>>>> used the code you mentioned and then runopf(mpc), convergence fails. In
>>>>>> general, how to add box constraints for Va,Vm, Pg and Qg of xr (r =
>>>>>> runopf(mpc); r.raw.xr).
>>>>>> If I have to use the add_constraints function, how do I do that?
>>>>>>
>>>>>> Regards
>>>>>> Viswanath Hariharan
>>>>>>
>>>>>> On Wed, Sep 27, 2017 at 1:39 PM, Ray Zimmerman <r...@cornell.edu>
>>>>>> wrote:
>>>>>>
>>>>>>> Voltage magnitude constraints are already included. Simply set the
>>>>>>> VMIN and VMAX columns in the bus matrix to the desired values.
>>>>>>>
>>>>>>> For voltage angles, simply define the A, l and u corresponding to
>>>>>>> equation (6.25) in the User’s Manual
>>>>>>> <http://www.pserc.cornell.edu/matpower/docs/MATPOWER-manual-6.0.pdf>.
>>>>>>> Something like the following …
>>>>>>>
>>>>>>> mpc = loadcase(<your-case-name>);
>>>>>>> nb = size(mpc.bus, 1);
>>>>>>> ng = size(mpc.gen, 1);
>>>>>>> mpc.A = sparse(1:nb, 1:nb, 1, nb
>>>>>>> <https://maps.google.com/?q=1:nb,+1,+nb&entry=gmail&source=g>,
>>>>>>> 2*nb+2*ng);
>>>>>>> mpc.u = 0.26 * ones(nb, 1);
>>>>>>> mpc.u = -mpc.l;
>>>>>>>
>>>>>>> — Ray
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> On Sep 23, 2017, at 5:25 PM, Viswanath Hariharan <
>>>>>>> vhari...@buffalo.edu> wrote:
>>>>>>>
>>>>>>> Hello Sir
>>>>>>>
>>>>>>> I want to add voltage magnitude and voltage angle constraints to the
>>>>>>> opf solver but I am not able to figure out how to.
>>>>>>>
>>>>>>> Voltage magnitude constraints ---> 0.9 <= Vm <= 1.1
>>>>>>> Voltage angle constraints ---> - 0.26 <= Va <= 0.26 (Unrelaxed form)
>>>>>>>
>>>>>>> I read a post where you mentioned to add these constraints to the
>>>>>>> case
>>>>>>> struct which looked pretty simple in the post but I didn't know how
>>>>>>> to add
>>>>>>> that to the case struct.
>>>>>>> I was wondering if you can guide me on how to do it. Hoping to hear
>>>>>>> from
>>>>>>> you soon.
>>>>>>>
>>>>>>> Regards
>>>>>>> Viswanath Hariharan
>>>>>>> Graduate Research Assistant
>>>>>>> Electrical Engineering
>>>>>>> University at Buffalo
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>
>
>
