I found multiple problems with your case file ‘radial_case_no_null.m’. First of all, buses 30 and 36 are connected to each other, but not to the rest of the system, and buses 92 and 93 are completely isolated. Second, check the columns of your gen matrix. It looks to me like you missed the VG column or something. Currently you have both GEN_STATUS and PMAX set to 999999. And, by the way, if you mean for it to be unbounded, simply use Inf, instead of 999999.
Ray > On Dec 18, 2014, at 4:49 AM, ALI ZAZOU Abdelkrim > <[email protected]> wrote: > > Hi, > > I'm actually stuck with trying to solve the load flow for a radial > distribution, and i need your help because i really don't know what to do. > > The system is composed of 91 nodes and 1 generator, i attached to this > message the test case with null and non null values. > This case don't converge to a result, and matlab tells me: > > "Warning: Matrix is singular to working precision. >> In newtonpf at 186 > In runpf at 226" > > So i fisrtly thought that null values in bus Pd, Qd was the problem but even > when i put small value to it, it don't solve the problem. > I tried to see where the values become null or infinite and it comes from the > computation of "dx=-(J/F)" > J and F have non null value but are big (~1e+6) > > I also think that BR_R and BR_X are to small, so to be sure here is my per > unit calculation: > > S_ref=10Mva, V_ref=20Kv > Z_ref=(20000^2)/(10000000/3) > And for P an Q values are in MW and MVar > > And i also tried to run a continuation PF but it can't handle "nan" values. > > > So what can you advice to me to try to find a solution ? > > Thank you very much > Best regards > Abdelkrim Ali zazou > > > > <radial_case_no_null.m><radial_case_null.m><radial_case.png>
