fix: apply sum term bypassing for control model type 1

Author: mvelasqu

src/parsers/pm_io/psse.jl

@@ -739,8 +739,9 @@ function _psse2pm_shunt!(pm_data::Dict, pti_data::Dict, import_all::Bool)
                 error("Unsupported PSS(R)E source version: $(pm_data["source_version"])")
             end
 
-            if modsw ∈ (0, 2)
-                # In fixed/continuous mode, BINIT is the total shunt admittance.
+            if modsw ∈ (0, 1, 2)
+                # For fixed/discrete/continuous modes used for PF comparison,
+                # BINIT is treated as the total shunt admittance.
                 # Keep Y_increase but zero all initial states to avoid double counting.
                 sub_data["initial_status"] = zeros(Int, length(sub_data["y_increment"]))
             end