First, >> mpct.bus(:,[PD QG]) = mpcb.bus(:,[PD QG])*2.5; is incorrect if you trying >> to scale both the real and the reactive power load. It should be mpct.bus(:,[PD QD]) = mpcb.bus(:,[PD QD])*2.5;
Even after making this change, the CPF does not converge at the last step. This is because it overshoots (crosses lam = 0) in the previous step and cannot recover after that due to a negative step. I can also see that there is a big difference between the predicted and correction solutions at the last step. It will take a bit of investigation to fix this properly. In the meantime, as a quick fix, you can change line 292 in runcpf() if abs(lam) < 1e-8 to if lam < 1e-8 The only caveat is that now cpf won't stop exactly at lam = 0, but it will overshoot (which I presume may be fine with you?) Shri From: Natakorn Thasnas <[email protected]<mailto:[email protected]>> Reply-To: MATPOWER discussion forum <[email protected]<mailto:[email protected]>> Date: Fri, 13 Feb 2015 01:05:23 +0700 To: MATPOWER discussion forum <[email protected]<mailto:[email protected]>> Subject: Re: PV Curve Please see the base case file in attachment Natakorn 2015-02-13 0:57 GMT+07:00 Abhyankar, Shrirang G. <[email protected]<mailto:[email protected]>>: Can you please send your base case file. Shri From: Natakorn Thasnas <[email protected]<mailto:[email protected]>> Reply-To: MATPOWER discussion forum <[email protected]<mailto:[email protected]>> Date: Fri, 13 Feb 2015 00:21:15 +0700 To: MATPOWER discussion forum <[email protected]<mailto:[email protected]>> Subject: Re: PV Curve Hi Shri I tried using a smaller continuation step size as your suggestion (step size=0.05). And I tried decreasing step size to 0.002, I still got the same result, the PV curve is not full nose curve. Best Regards, Natakorn Thasnas Ph.D Student Khonkaen University, Thailand 2015-02-12 20:41 GMT+07:00 Abhyankar, Shrirang G. <[email protected]<mailto:[email protected]>>: Try using a smaller continuation step size. mpopt = mpoption(mpopt, 'cpf.stop_at', 'full', 'cpf.step', 0.05); Shri > On Feb 12, 2015, at 4:03 AM, "Natakorn Thasnas" > <[email protected]<mailto:[email protected]>> wrote: > > Hi All > > I am trying to run a continuation power flow with the following code > > define_constants; > mpopt = mpoption('out.all', 0, 'verbose', 2); > mpopt = mpoption(mpopt, 'cpf.stop_at', 'full', 'cpf.step', 0.2); > mpopt = mpoption(mpopt, 'cpf.plot.level', 2 ,'cpf.plot.bus', 14); > mpcb = loadcase('case14result'); % load base case > mpct = mpcb; % set up target case with > mpct.gen(:, [PG QG]) = mpcb.gen(:, [PG QG])*2.5; > mpct.bus(:,[PD QG]) = mpcb.bus(:,[PD QG])*2.5; > results = runcpf(mpcb, mpct, mpopt); > > After running it, I got the warning message "corrector did not converge in > 1000 iterations" and the PV curve is not full nose curve as showing in > attached file (c14.jpg) > > <c14.jpg> > > Then I increased "max_it" ​from 1000 to 10000. I got the warning messages as > following > > Warning: Matrix is close to singular or badly scaled. > Results may be inaccurate. RCOND = 1.944067e-018. > > In cpf_corrector at 143 > In runcpf at 268 > In cpfrun at 55 > step 48 : lambda = -7.770, corrector did not converge in 10000 iterations > > > Could you please suggest me how to fix it to get "the full nose curve"? > > Thank you in advance. > > Best Regards, > > Natakorn Thasnas > Ph.D Student > Khonkaen University, Thailand
