Calculates base-resistance depending on the choice of units.
"pu":
R_base = V_nom*V_nom/S_nom"SI":
R_base = 1
function baseR extends Icons.Function; input Base.Types.Units units "SI or pu"; input SI.Voltage V_nom "nom voltage"; input SI.ApparentPower S_nom "apparent power"; input Integer scale = 1 "scaling factor topology (Y:1, Delta:3)"; output SI.Resistance R_base "base resistance"; end baseR;