Dear Matpower Community, I am observing a strange problem whereby the results from a successful 'runopf()' do not seem to present a solved power flow case. I want to verify the power flow solution from an OPF by running a PF with the OPF results as the mpc struct. Firstly, the 'runpf()' converges in 1 iteration, whereas i would expect a solved case to converge in 0 iterations- am i mistaken here? Secondly, when i use the 'compare_case()' command to compare the OPF results with the resulting PF results, I see that there are large differences between the solutions. My code is as follows:
resultsOPF=runopf(mpc123); resultsPF=runpf(resultsOPF); compare_case(resultsOPF, resultsPF) The comparison shows a maximum reactive power difference of 494 MVAR between the generator results: gen PG 5.00578e-10 9.67145e-09 9.17088e-09 614 QG 7.99959e-11 494.118 494.118 218 * The OPF command converges successfully with no error warnings, and so I assumed that running the results struct through a PF command should give the same power flow solution. Am i mistaken here? If my thinking is correct, this would indicate that the optimiser has provided results that do not represent a feasible power flow solution - is this potentially a bug? I have tested the same method on the 'case14.m' file and observe that this also requires 1 iteration to converge and gives very small differences (~2e-7) between the OPF and PF results. I am using the latest matpower release (5.0), the TSPOPF 5.0 solver and a windows 7 machine (see output of mpver at end of email). I have tried with other solvers and observe the same problem. I am working with a large model (>5000 bus) that i have attached below. Could the size of my model be the cause of this problem? Presently I am not sure whether I am making a simple mistake or if there is a bug in the solver that is causing the output of inaccurate results. Has anyone experienced similar problems? I would very much appreciate any advice on the cause of the problem. Kind Regards, Dominic mpver MATPOWER Version 5.0 17-Dec-2014 MATLAB Version 8.4 08-Sep-2014 Release: (R2014b) Optimization Toolbox Version 7.1 08-Sep-2014 Release: (R2014b) MIPS Version 1.1 17-Dec-2014 SDP_PF -- not installed -- YALMIP -- not installed -- BPMPD_MEX -- not installed -- CPLEX Version 12.6.0.0 PCWIN64 Gurobi -- not installed -- GLPK -- not installed -- IPOPT -- not installed -- KNITRO -- not installed -- MINOPF -- not installed -- MOSEK -- not installed -- PDIPMOPF Version 5.0 17-Dec-2014 PCWIN64 SCPDIPMOPF Version 5.0 17-Dec-2014 PCWIN64 SDPT3 -- not installed -- SeDuMi -- not installed -- TRALMOPF Version 5.0 17-Dec-2014 PCWIN64 Architecture: PCWIN64
mpc123.mat
Description: mpc123.mat
