The first issue is most likely related to switching off a transmission line and by so doing creating a disconnected network. MATPOWER should be able to handle this case if you can ensure that there is a voltage reference bus in each island.
In the second case, there is no longer any network. In theory, such a problem should have a solution if all buses are converted to reference buses, but that is such a degenerate case that I'm nearly certain MATPOWER will not be able to handle it. I'm afraid you'll have to find a different way to solve that problem. -- Ray Zimmerman Senior Research Associate 419A Warren Hall, Cornell University, Ithaca, NY 14853 phone: (607) 255-9645 On Feb 22, 2013, at 10:42 AM, Jiashen Teh <[email protected]> wrote: > Dear Dr Ray, > > May I know why I have this error message as follow: > > Error using opf_model/add_constraints (line 102) > @opf_model/add_constraints: number of columns of A does not match > number of variables, A is 24 x 71, nv = 72 > > Error in opf_setup (line 228) > om = add_constraints(om, 'Pmis', Amis, bmis, bmis, {'Va', 'Pg'}); %% nb > > Error in opf (line 219) > om = opf_setup(mpc, mpopt); > > Error in runopf (line 96) > [r, success] = opf(casedata, mpopt); > > Error in rundcopf (line 94) > [varargout{1:nargout}] = runopf(casedata, mpopt, fname, solvedcase); > > I run DCOPF for few thousand loops. Randomly at certain iterations only, i > will have the above message shown. > > During each iterations, i will randomly switch on and off certain generators > and transmission line. The weird thing is that I only have problems at > certain particular iteration(s) and not before or after the problematic > iteration. > > May I know why? Thanks in advance. > > On Second issue, i think this is related as well. > I add an additional expensive generator at all load buses with sufficient > generation to meet the load and disable all transmission lines. when I run > DCOPF in this condition, MATLAB will show me "exceeds matrix index error > message". > > Yours sincerely, > > Jiashen Teh > PhD Student > Electrical Energy & Power Systems Group, School of Electrical & Electronic > Engineering > Ferranti Building (B18), The University of Manchester, M13 9PL, United Kingdom > Tel: +44 (0) 161 306 2263; Mobile: +44 (0) 792 322 4864
