Thanks Ray very much for your support! I greatly appreciate it
I will it give the code a go and come back to you with feedback
Thanks and regards
Mariusz
From: bounce-124729090-81515...@list.cornell.edu
<bounce-124729090-81515...@list.cornell.edu> On Behalf Of Ray Daniel Zimmerman
Sent: Wednesday, June 24, 2020 4:10 PM
To: MATPOWER-L <matpowe...@list.cornell.edu>
Subject: Re: Extension to AC OPF - soft limits
I don’t think there is a way to do this using the existing soft limits
functionality in MATPOWER. However, it should be fairly straightforward to
implement using user-defined linear constraints and costs, since all of your
constraints and costs are linear. The simplest approach would probably be to
use Direct Specification as described in Section 7.1 of the User’s Manual.
Simply add A, l and u as extra fields in mpc to defined the constraints, with
extra columns in A to define the s and T variables. Then add N and Cw as extras
fields to define the cost on the new T variable (using the legacy cost format).
I suppose you will also want to set the generator costs to zero in the gencost
matrix.
For example, A and N can be defined with 2*nb + 4*ng + 1 columns, corresponding
to Va, Vm, Pg, Qg, sm, sp, T. The following (untested) code, should at least be
close to what you want …
nb = size(mpc.bus, 1);
ng = size(mpc.gen, 1);
I = speye(ng,ng); % ng x ng identity matrix
Zb = sparse(ng, nb); % ng x nb zero matrix
Zg = sparse(ng, ng); % ng x ng zero matrix
% -Pg - sm <= -Plower
A1 = [Zb Zb -I Zg -I Zg 0];
u1 = -Plower;
% Pg - sp >= Pupper
A2 = [Zb Zb I Zg -I Zg 0];
u2 = Pupper;
% sm - T <= 0
A3 = [Zb Zb Zg Zg I Zg -1];
u3 = zeros(ng, 1);
% sp - T <= 0
A4 = [Zb Zb Zg Zg Zg I -1];
u4 = zeros(ng, 1);
mpc.A = [A1; A2; A3; A4];
mpc.u = [u1; u2; u3; u4];
mpc.N = [sparse(1, 2*nb+4*ng) 1]; % select T
mpc.Cw = 1;
Let me know how it works,
Ray
On Jun 23, 2020, at 2:58 PM, m.drabe...@onet.eu <mailto:m.drabe...@onet.eu>
wrote:
Dear community,,
I am now working with soft limits on generation in AC-OPF. I know that these
are natively supported by Matpower.
However, I would like to change the formulation so to minimize the maximum
value of limit violation on P_G , i.e. as in the model below:
<image001.jpg>
I would like to ask you all if this is anyhow supported by Matpower ? If yes,
what would be the easiest way to do that?
Thanks in advance and regards,
Mariusz Drabecki,
Operations and Systems Research Division
Institute of Control and Computation Engineering
Warsaw University of Technology
