I tried it with several solvers that claim the problem is infeasible. The best way I know to find out why is to start with a feasible case and modify things gradually until you see which constraints bind and then finally become infeasible. You might try applying your changes little by little, say using a weighted average of the parameters from the original case57 and yours, to see if you can see which constraints bind first.
-- Ray Zimmerman Senior Research Associate 419A Warren Hall, Cornell University, Ithaca, NY 14853 phone: (607) 255-9645 On Apr 5, 2013, at 8:18 AM, Khirad Dhabhar <[email protected]> wrote: > Dear sir > > I made the following modifications in the 57 test case file > > 1 set Pmin of all generators values are given below > bus no Pmin val > 1 120 > 2 30 > 3 50 > 6 20 > 8 100 > 9 20 > 12 80 > > 2 The values of Bs (column 6 of bus data ) are changed to the following (the > original file the absolute values so i changed them to p.u values on a 100MVA > base. i.e divided by 100 I did this as in case 30 bus the values are in P.u.) > > When i type runopf(case57) > > its says > > MATPOWER Version 4.1, 14-Dec-2011 -- AC Optimal Power Flow > MATLAB Interior Point Solver -- MIPS, Version 1.0, 07-Feb-2011Warning: Matrix > is close to singular or badly scaled. > Results may be inaccurate. RCOND = 4.999312e-023. > > In mips at 422 > In mipsopf_solver at 145 > In opf_execute at 106 > In opf at 225 > In runopf at 96 > > Numerically Failed > > Did not converge in 16 iterations. > > Did not converge (0.62 seconds) > > Objective Function Value = 44558.59 $/hr > > i have attached the case file > > > > > > -- > Friendship is like a red rose with a green stem > <case57.m>
