Value Error and Invalid loading percent
When running asymmetric loadflow in pandapower using runpp_pgm and with option trafo_loading="Current", a value error occurs in pandapower_converter.py at _pp_trafos_output_3ph function because "i_from" and "i_to" have shape (n,3) while "u1" and "u2" have shape (n,). Moreover, the loading calculation is invalid; for phase wise loading, the voltage "u" which is line-to-line needs to be converted to line-to-phase by dividing with sqrt(3), moreover, the phase power needs to be divided with sn_phase = sn / 3.