Thanks Ray, but I do have a reference bus and my case file is giving me the
right results when I run a pf or opf.
My network has 80 buses and two generators, on of which is a refernce bus.
From: [email protected]
Subject: Re: Branch minimisation loss error message
Date: Mon, 17 Sep 2012 09:17:07 -0400
To: [email protected]
It means that you do not have a reference bus defined in your case file. One of
the buses should have the BUS_TYPE column (2) set to REF (3).
-- Ray ZimmermanSenior Research Associate419A Warren Hall, Cornell University,
Ithaca, NY 14853phone: (607) 255-9645
On Sep 14, 2012, at 1:41 AM, Richard Ngonga wrote:I am getting the following
error message whenever I try running a user defined program to minimize branch
losses(min_power_exchange) using my case file. This problem doesn't occur when
I try running the program with a Matpower supplied case file. Can you please
tell me what the error message means?
??? Attempted to access Varefs(1); index out of bounds because numel(Varefs)=0.
Error in ==> mipsopf_solver at 127
x0(vv.i1.Va:vv.iN.Va) = Varefs(1); %% angles set to first reference angle
Error in ==> opf_execute at 106
[results, success, raw] = feval(solver, om, mpopt);
Error in ==> opf at 225
[results, success, raw] = opf_execute(om, mpopt);
Error in ==> runopf at 96
[r, success] = opf(casedata, mpopt);
Error in ==> min_power_exchange at 237
[results, success] = runopf(mpc, mpopt);
Error in ==> testng at 15
results = min_power_exchange(mpc,mpopt);
Bellow is my program code
mpc = loadcase('case803.m');
mpopt = mpoption(
'VERBOSE',0,'OUT_ALL',0);
mpc = runopf(case803,mpopt);
define_constants;
% %% create map of external bus numbers to bus indices
i2e = mpc.bus(:, BUS_I);
e2i = sparse(max(i2e), 1);
e2i(i2e) = (1:size(mpc.bus, 1))';
% %% ties lines
ties = find(mpc.bus(e2i(mpc.branch(:, F_BUS)), BUS_AREA) ~=
mpc.bus(e2i(mpc.branch(:, T_BUS)), BUS_AREA));
ties_idx = [mpc.branch(ties, F_BUS) mpc.branch(ties, T_BUS)];
flow_t0 = [mpc.branch(ties, PF) mpc.branch(ties, QF)];
% % Reduction of the load at bus 26
%mpc.bus(26,[PD QD]) = 0.8*mpc.bus(26,[PD QD]);
results = min_power_exchange(mpc,mpopt);
flow_tf = [results.branch(ties, PF) results.branch(ties, QF)];
% % difference of the tie flows
flow_t0 - flow_tf
