So can you confirm each of the follow? - You say that the AC OPF converges but the DC OPF claims infeasibility, correct? - You’ve checked the system data … case_info() output looks good (no islands, 1 reference bus, generation range adequate to serve total load, etc.). - Removing line limits (by setting RATE_A to 0) does not make that problem feasible? - You are using the Optimization Toolbox default solver (linprog or quadprog with interior point solver).
If so, can you try with a simplex solver (dual simplex is probably best) and see if that gives a different result? Ray > On Jun 30, 2016, at 1:31 AM, anshu dahiya <[email protected]> wrote: > > sir i have already relaxed my line limits. but it doesn't give any response! > > > On Wed, Jun 29, 2016 at 6:29 PM, Ray Zimmerman <[email protected] > <mailto:[email protected]>> wrote: > It appears that your solver thinks the problem is infeasible. Try relaxing > the branch flow limits to see if it solves. e.g. > > define_constants; > mpc = loadcase(<your case file>); > mpc.branch(:, RATE_A) = mpc.branch(:, RATE_A) * 2; % double the flow limits > r = rundcopf(mpc); > > Or instead of doubling the limits, you could temporarily eliminate them > completely. > > mpc.branch(:, RATE_A) = 0; % eliminates line flow limits completely > > > Ray > > >> On Jun 29, 2016, at 5:19 AM, anshu dahiya <[email protected] >> <mailto:[email protected]>> wrote: >> >> sir my acopf is running but not the dcopf what may be cause? The error >> comes in the matpower is as below: >> rundcopf(n84) >> >> MATPOWER Version 5.1, 20-Mar-2015 -- DC Optimal Power Flow >> The interior-point algorithm uses a built-in starting point; >> ignoring user-supplied X0. >> Exiting: One or more of the residuals, duality gap, or total relative error >> has grown 100000 times greater than its minimum value so far: >> the primal appears to be infeasible (and the dual unbounded). >> (The dual residual < TolFun=1.00e-08.) >> >> >>>>> Did NOT converge (0.06 seconds) <<<<< >> >> On Mon, Jun 27, 2016 at 5:44 PM, Saranya A <[email protected] >> <mailto:[email protected]>> wrote: >> Hi Anshu, >> >> Even I faced a similar problem with a different system. In "mpc.branch" the >> 6th, 7th and 8th columns represent RATE A - MVA rating A (long term rating) >> ,RATE B - MVA rating B (short term rating), RATE C - MVA rating C (emergency >> rating) respectively. Try giving a high MVA rating to all the 3 columns and >> check if your solution converges. >> >> Regards, >> Saranya.A >> >> On Mon, Jun 27, 2016 at 1:08 PM, anshu dahiya <[email protected] >> <mailto:[email protected]>> wrote: >> i have double check my data it is giving the below error: >> runopf(c84) >> >> MATPOWER Version 5.1, 20-Mar-2015 -- AC Optimal Power Flow >> MATLAB Interior Point Solver -- MIPS, Version 1.2, 20-Mar-2015 >> (using built-in linear solver) >> Numerically Failed >> >> Did not converge in 6 iterations. >> >> >>>>> Did NOT converge (0.09 seconds) <<<<< >> >> >> On Mon, Jun 27, 2016 at 11:51 AM, Fiaz Ahmad <[email protected] >> <mailto:[email protected]>> wrote: >> If there is no syntax error then check your branch matrix. It has high R and >> X values,it will not converge. Probably you are not using the correct per >> unit values. Your zbase=vbase*vbase/mvabase. Use zbase to find p.u values >> for R and X. >> >> I hope it helps >> >> On Jun 27, 2016 8:53 AM, "anshu dahiya" <[email protected] >> <mailto:[email protected]>> wrote: >> sir my system is not converging while performing opf and dcopf , what should >> i check in my program. Plz help me >> >> On Sun, Jun 26, 2016 at 5:53 AM, anshu dahiya <[email protected] >> <mailto:[email protected]>> wrote: >> the problem is still as it was. my 84 bus system is still not converging >> after applying all steps directed by the Dr. Ray Zimmerman . can anyone help >> me to make the system converge. i am attaching my file >> >> On Fri, Jun 24, 2016 at 6:24 PM, Ray Zimmerman <[email protected] >> <mailto:[email protected]>> wrote: >> See FAQ #5 <http://www.pserc.cornell.edu/matpower/#pfconvergence>. >> >> Ray >> >> >>> On Jun 24, 2016, at 3:42 AM, anshu dahiya <[email protected] >>> <mailto:[email protected]>> wrote: >>> >>> my 84 bus system is not converging into 10 iteration. what should i take >>> steps to make it converge. >>> >>> On Thu, Jun 23, 2016 at 8:43 PM, Ray Zimmerman <[email protected] >>> <mailto:[email protected]>> wrote: >>> Whenever you have a problem with a case file, the first thing to do is >>> always run case_info() >>> <http://www.pserc.cornell.edu/matpower/docs/ref/matpower6.0b1/case_info.html> >>> to check for errors in the connectivity information … >>> >>> >> case_info('casem84') >>> Bad bus numbers: 1 >>> bus(1, BUS_I) = 0 >>> >>> Turns out that bus numbers must be positive integers, as stated in >>> caseformat >>> <http://www.pserc.cornell.edu/matpower/docs/ref/matpower6.0b1/caseformat.html>. >>> >>> Ray >>> >>> >>> >>>> On Jun 23, 2016, at 1:59 AM, anshu dahiya <[email protected] >>>> <mailto:[email protected]>> wrote: >>>> >>>> sir how to solve the following error in matpower which comes in the case84 >>>> which i have attached >>>> Error using sparse >>>> Index into matrix must be positive. >>>> >>>> Error in ext2int (line 141) >>>> n2i = sparse(mpc.bus(:, BUS_I), ones(nb, 1), 1:nb, >>>> max(mpc.bus(:, BUS_I)), 1); >>>> >>>> Error in runpf (line 111) >>>> mpc = ext2int(mpc); >>>> >>>> On Wed, Jun 22, 2016 at 6:59 PM, Ray Zimmerman <[email protected] >>>> <mailto:[email protected]>> wrote: >>>> Assuming this is for a power flow problem, you still have to decide >>>> whether the bus is voltage controlled or not. If so, make it a PV bus. If >>>> not, and the DG simply injects a fixed amount of power without controlling >>>> voltage, then make it a PQ bus. >>>> >>>> Ray >>>> >>>> >>>> >>>> > On Jun 22, 2016, at 1:27 AM, anshu dahiya <[email protected] >>>> > <mailto:[email protected]>> wrote: >>>> > >>>> > how to nominate DG bus which has load as well as generation >>>> > the nomenclature in the matpower as below >>>> > 1= PQ bus >>>> > 2= PV bus >>>> > 3= reference bus >>>> > 4= isolated bus >>>> > i have attached my file plz take a look of it. suggest me solution. >>>> > <casem84.m> >>>> >>>> >>>> >>>> >>>> <casem84.m> >>> >>> >> >> >> >> >> >> > >
