Thanks Dr zimmerman. an you adress the following points, please? 1. When I did the same simulation, r.success was 1 not 0. 2. why matpower can not solve this case? 3. I did this simulation with gauss-sidel. the results were the same with those of newton-raphson. 4. How can I solve this problem with matpower?
Kind Regards Ahmad ________________________________ From: Ray Zimmerman <[email protected]> To: MATPOWER discussion forum <[email protected]> Sent: Thursday, April 4, 2013 7:59 AM Subject: Re: outage of line 14 in IEEE 14 bus test system >> define_constants >> mpc = loadcase('case14'); >> mpc.branch(14, BR_STATUS) = 0; >> opt = mpoption('OUT_ALL', 0); >> r = runpf(mpc, opt); MATPOWER Version 4.1+, 28-Nov-2012 -- AC Power Flow (Newton) Warning: Matrix is singular to working precision. > In newtonpf at 109 In runpf at 224 <warning repeated 9 more times> Newton's method power did not converge in 10 iterations. >> r.success ans = 0 The results are telling you that the power flow did not converge (that is, it was unable to find a solution) … and that information is "correct and reliable" ;-) … so, no, any bus voltages, flows, etc will not correspond to a solved power flow. -- Ray Zimmerman Senior Research Associate 419A Warren Hall, Cornell University, Ithaca, NY 14853 phone: (607) 255-9645 On Apr 4, 2013, at 4:55 AM, ahmad rezaee <[email protected]> wrote: Dear Dr Zimmerman > > >In IEEE 14 bus test system when I make out line 14 and run power flow, >matpower messages: "Warning: Matrix is singular to working precision.". This message means that jacobian matrix is singular. Yes? Matpower gives me some results for power flow. Are the results correct and reliable? (I know this problem occurs since bus 8 will be islanded.) > > >Kind regards > >Ahmad
