Re: MOST

[Ammar Raza]

Hi Ray,

Thank you for your email.

Kind Regard,

Mohammad Ammar Raza




On 17 May 2017 at 14:51, Ray Zimmerman  wrote:

> Hi Mohammad,
>
> A unit commitment problem with quadratic generator costs or ramping costs
> requires a solver that can handle Mixed Integer Quadratic Programming
> (MIQP) problems. The only MATPOWER-compatible solvers that handle MIQP are
> Gurobi, CPLEX and MOSEK, as stated in the System Requirements section of
> the MOST User’s Manual.
>
> So, you will either need to install one of these solvers, or modify your
> problem so that in does not include any quadratic costs.
>
>Ray
>
>
> On May 16, 2017, at 5:30 PM, Ammar Raza  wrote:
>
> Hi
>
> I am trying to do example 6 of the MOST user manual with Bus 118 and I got
> this error.
>
> Error using mpopt2qpopt (line 92)
> mpopt2qpopt: Sorry, no solver available for MIQP models
>
> Error in most (line 2065)
>   mdo.QP.opt = mpopt2qpopt(mpopt, model, 'most');
>
> Error in most_ammar6 (line 108)
> mdo = most(mdi, mpopt);
>
>
> Kind Regard,
>
> Mohammad Ammar Raza
>
>
>
>
> On 15 May 2017 at 20:14, Ray Zimmerman  wrote:
>
>> In a deterministic problem, transmat can simply be a scalar with the
>> number of periods. See the description of transmat in the help for
>> loadmd()
>> 
>> .
>>
>>Ray
>>
>>
>>
>> On May 15, 2017, at 7:37 AM, Ammar Raza  wrote:
>>
>> Thank you Ray
>>
>> Therefore, Transmat should be like that?
>>
>> transmat = cell(1, nt);
>> T = [ 1x 99];
>> [transmat{:}] = deal(T * ones(1,1));
>> transmat{1} = T;
>>
>> Kind Regard,
>>
>> Mohammad Ammar Raza
>>
>>
>>
>>
>> On 11 May 2017 at 13:42, Ray Zimmerman  wrote:
>>
>>> Just to clarify, if loadprofile.rows  = 0, then loadprofile.values(:,
>>> 1, :) = [24 x 1] and all loads are scaled together. Otherwise, the
>>> number of columns in loadprofile.values(:, 1, :) must equal the length
>>> of loadprofile.rows and each of the specified loads is scaled
>>> separately.
>>>
>>>Ray
>>>
>>>
>>> On May 9, 2017, at 10:29 AM, Ammar Raza  wrote:
>>>
>>> Its means
>>>
>>> loadprofile.rows= [1 x 99 ]
>>>
>>> Thanks Stephanie for your help.
>>>
>>> Kind Regard,
>>>
>>> Mohammad Ammar Raza
>>>
>>>
>>>
>>>
>>> On 9 May 2017 at 15:25, Stephanie  wrote:
>>>
 Yes, and the value of rows, 0 means the load is applied to the all
 buses, so you should also change the value of the rows by 
 loadprofile.rows=load_index
 (e.g. loadprofile.rows=[2 3 5]), if there are three loads located in bus 2,
 3 and 5, respectively)

 Best Regards,
 Stephanie

 2017-05-09 22:09 GMT+08:00 Ammar Raza :

> that means
>
> loadprofile = struct( ...
> 'type', 'mpcData', ...
> 'table', CT_TLOAD, ...
> 'rows', 0, ...
> 'col', CT_LOAD_ALL_PQ, ...
> 'chgtype', CT_REP, ...
> 'values', [] );
>
> loadprofile.values(:, 1, :) = [ 24 x 99 ]
>
>
> Kind Regard,
>
> Mohammad Ammar Raza
>
>
>
>
> On 9 May 2017 at 14:55, Stephanie  wrote:
>
>> Hi,
>>
>> I tried it a few days before, what I did is:
>>
>> loadprofile.rows=load_index; %which applies the load to the bus it
>> locates
>> loadprofile.value (:,1,:) = [24 x 99];
>>
>> And it works in my situation
>>
>> Hope it will help you
>> --
>> Best Regards
>> Stephanie
>>
>>
>> *From:* Ammar Raza 
>> *Date:* 2017-05-09 21:43
>> *To:* MATPOWER discussion forum 
>> *Subject:* MOST
>> Hi all,
>>
>> I am working on bus 118 with 54 generator and 99 loads.
>>
>> I would like to ask you for the multi period problem i.e. 24 hours,
>> how I will make the load profile function. Can I do like that
>>
>> loadprofile.value (:,1,1) = [24 x 99];
>>
>>
>>
>> As in case3a in the MOST manual there is only one load therefore,
>> load profile matrix is [12 x 1]
>>
>> loadprofile.value(:,1,1)=[
>> 440;
>> 480;
>> ..
>> ..
>> .. ];
>>
>>
>> Kind Regard,
>>
>> Mohammad Ammar Raza
>>
>>
>>
>>
>

>>>
>>>
>>
>>
>
>

Re: Power flow VM VA, CPF end point

[Elis Nycander]

I see, that's interesting. Thanks!

2017-05-22 10:00 GMT+02:00 Jose Luis Marín :

>
> 1. Yes, VM VA are used both for input and output. Note one subtle point,
> though: in runpf.m (Lines 177--183) the initial seed for the iteration is
> first set to the values [VM VA] provided as input, but for
> voltage-controlled buses (with active generators), the value of VM is
> replaced by the setpoint VG of their respective bus generator(s) (the value
> of VA is preserved). This makes sense because it guarantees that the seed
> will be closer to the solution.
>
> 2. What you see here is to be expected. Basically, what happens is that
> the basins of attraction of low-voltage volutions are usually smaller than
> those of the operating solution. Also, note that there are *many* (for N
> buses, somewhat of the order of 2^N) low voltage solutions, so chances are
> that the iteration will converge to a solution that's different from the
> one you followed by homotopy (CPF). Even homotopy methods can encounter
> this same problem if their step-size is not small enough.
>
>
> Here's some refs on the fractal nature of the problem:
>
> @INPROCEEDINGS{KlumpOverbye00b,
> author={Klump, R.P. and Overbye, T.J.},
> booktitle={Power Engineering Society Summer Meeting},
> title={A new method for finding low-voltage power flow solutions},
> publisher={IEEE},
> year={2000},
> volume={1},
> pages={593--597},
> doi={10.1109/PESS.2000.867653},
> ISSN={}
> }
>
> @INPROCEEDINGS{ThorpNaqavi89,
> author={Thorp, J.S. and Naqavi, S.A.},
> booktitle={Proceedings of the 28th IEEE Conference on Decision and
> Control},
> title={Load flow fractals},
> year={1989},
> volume={2},
> pages={1822--1827},
> doi={10.1109/CDC.1989.70472}
> }
>
> @INPROCEEDINGS{ThorpNaqaviChiang90,
> author={Thorp, J.S. and Naqavi, S.A. and Chiang, H.-D.},
> booktitle={Decision and Control, 1990., Proceedings of the 29th IEEE
> Conference on},
> title={More load flow fractals},
> year={1990},
> month={dec},
> volume={6},
> pages={3028--3030},
> doi={10.1109/CDC.1990.203339}
> }
>
> @ARTICLE{ThorpNaqavi97,
> author={Thorp, J.S. and Naqavi, S.A.},
> journal=IEEE_M_CAP,
> title={Load-flow fractals draw clues to erratic behaviour},
> year={1997},
> month={jan},
> volume={10},
> number={1},
> pages={59--62},
> doi={10.1109/67.560872},
> ISSN={0895-0156}
> }
>
> @INPROCEEDINGS{Mori00,
> author={Mori, H.},
> booktitle={IEEE International Symposium on Circuits and Systems (ISCAS)},
> title={Chaotic behavior of the Newton-Raphson method with the optimal
> multiplier for ill-conditioned power systems},
> year={2000},
> volume={4},
> pages={237--240},
> doi={10.1109/ISCAS.2000.858732}
> }
>
>
> --
> Jose L. Marin
> Grupo AIA
>
>
>
>
> 2017-05-19 11:30 GMT+02:00 Elis Nycander :
>
>> Hi all matpower users!
>>
>> I have two questions:
>>
>> 1. In the bus matrix, the columns VM and VA are used both for the initial
>> guess when solving the power flow, and to store the resulting voltages?
>>
>> 2. When solving a cpf, I get lam_max which corresponds to the nose point,
>> i.e. maximum load/generation increase before "voltage collapse" happens. I
>> can also find the power flow at the nose point just by running an ordinary
>> power flow with flat start and conditions corresponding to the maximum
>> load. However, I have tried to do the same thing for the lower part of the
>> PV curve but failed to reproduce the solutions from the cpf. Basically I
>> thought I could get the lower part of the PV curve by just solving a power
>> flow using initial conditions which are close to the "unstable"/lower
>> solutions from the cpf (instead of a flat start), but I get different
>> solutions.
>>
>> Thanks,
>> Elis
>>
>
>

Re: Power flow VM VA, CPF end point

[Jose Luis Marín]

1. Yes, VM VA are used both for input and output. Note one subtle point,
though: in runpf.m (Lines 177--183) the initial seed for the iteration is
first set to the values [VM VA] provided as input, but for
voltage-controlled buses (with active generators), the value of VM is
replaced by the setpoint VG of their respective bus generator(s) (the value
of VA is preserved). This makes sense because it guarantees that the seed
will be closer to the solution.

2. What you see here is to be expected. Basically, what happens is that the
basins of attraction of low-voltage volutions are usually smaller than
those of the operating solution. Also, note that there are *many* (for N
buses, somewhat of the order of 2^N) low voltage solutions, so chances are
that the iteration will converge to a solution that's different from the
one you followed by homotopy (CPF). Even homotopy methods can encounter
this same problem if their step-size is not small enough.


Here's some refs on the fractal nature of the problem:

@INPROCEEDINGS{KlumpOverbye00b,
author={Klump, R.P. and Overbye, T.J.},
booktitle={Power Engineering Society Summer Meeting},
title={A new method for finding low-voltage power flow solutions},
publisher={IEEE},
year={2000},
volume={1},
pages={593--597},
doi={10.1109/PESS.2000.867653},
ISSN={}
}

@INPROCEEDINGS{ThorpNaqavi89,
author={Thorp, J.S. and Naqavi, S.A.},
booktitle={Proceedings of the 28th IEEE Conference on Decision and Control},
title={Load flow fractals},
year={1989},
volume={2},
pages={1822--1827},
doi={10.1109/CDC.1989.70472}
}

@INPROCEEDINGS{ThorpNaqaviChiang90,
author={Thorp, J.S. and Naqavi, S.A. and Chiang, H.-D.},
booktitle={Decision and Control, 1990., Proceedings of the 29th IEEE
Conference on},
title={More load flow fractals},
year={1990},
month={dec},
volume={6},
pages={3028--3030},
doi={10.1109/CDC.1990.203339}
}

@ARTICLE{ThorpNaqavi97,
author={Thorp, J.S. and Naqavi, S.A.},
journal=IEEE_M_CAP,
title={Load-flow fractals draw clues to erratic behaviour},
year={1997},
month={jan},
volume={10},
number={1},
pages={59--62},
doi={10.1109/67.560872},
ISSN={0895-0156}
}

@INPROCEEDINGS{Mori00,
author={Mori, H.},
booktitle={IEEE International Symposium on Circuits and Systems (ISCAS)},
title={Chaotic behavior of the Newton-Raphson method with the optimal
multiplier for ill-conditioned power systems},
year={2000},
volume={4},
pages={237--240},
doi={10.1109/ISCAS.2000.858732}
}


-- 
Jose L. Marin
Grupo AIA




2017-05-19 11:30 GMT+02:00 Elis Nycander :

> Hi all matpower users!
>
> I have two questions:
>
> 1. In the bus matrix, the columns VM and VA are used both for the initial
> guess when solving the power flow, and to store the resulting voltages?
>
> 2. When solving a cpf, I get lam_max which corresponds to the nose point,
> i.e. maximum load/generation increase before "voltage collapse" happens. I
> can also find the power flow at the nose point just by running an ordinary
> power flow with flat start and conditions corresponding to the maximum
> load. However, I have tried to do the same thing for the lower part of the
> PV curve but failed to reproduce the solutions from the cpf. Basically I
> thought I could get the lower part of the PV curve by just solving a power
> flow using initial conditions which are close to the "unstable"/lower
> solutions from the cpf (instead of a flat start), but I get different
> solutions.
>
> Thanks,
> Elis
>