Re: capacitive transformer branches in casefiles?

[Carlos E Murillo-Sanchez]

Hi; Looking at the diagram of the 118 bus system, it seems that the branches in question are a combination of  a transformer and a line.  Evidently, the pi model in the case data is an approximation of this combined setup.  But that is how the original data in the IEEE cdf file is coded. Carlos. Leon Thurner wrote: Dear All,   we are trying to translate the matpower casefiles to pandapower but have encountered problems when converting cases with transformers. We would expect transformers always to behave inductive, but the transformer branches in the cases always seem to have a positive b value. If I am not mistaken, that models a capacitive behaviour. An example of this can be found in case118 with the branches that connect buses 68 (345 kV) and bus 116 (138kV) as well as a branch that connects bus 86 (138kV) and bus 87 (161kV). Both of these branches have a positive susceptance while connecting different voltage levels.   Is there an explanation for that, i.e. do these branches not only model a transformer but a whole substation with reactive power compensation device as well? Or am I missing something else?   Thanks for your help Leon   ---------------------------------   Leon Thurner, M.Sc.   Universität Kassel Fachgebiet Energiemanagement und Betrieb elektrischer Netze Wilhelmshöher Alle 73 34121 Kassel   Tel.: +49 561 804 6377 E-Mail: leon.thur...@uni-kassel.de