Dear MATPOWER community, I am currently building a transmission system database for an emerging nation. When running an OPF simulation for this system, I encounter the problem of massive voltage drops over particularly long lines. This is hardly surprising, since some lines of the system are longer than 400 km. Combined with realistic reactances per km, this yields high per unit X (and B) values, and hence voltage drops. When I artificially reduce the reactance and susceptance values, I am able to achieve convergence.
My questions are: Is there a way of solving this issue, without tampering with the X and B values? I have played around with the tap ratios, but unfortunately, these are not within the parameters of the optimisation (i.e. they are fixed a priori). I have also tried adding a fictitious “reactive power generator” at each substation, without success. Any help would be appreciated. Thanks! Best Regards, Patrick Eser
