bugfix for undefined trafo3w characteristics

CHANGELOG.rst

@@ -42,6 +42,7 @@ Change Log
 - [ADDED] function :code:`outage_results_OTDF` to obtain the matrix of results for all outage scenarios, with rows as outage scenarios and columns as branch power flows in that scenario
 - [FIXED] add some safeguards for TDPF to avoid numerical issues in some cases
 - [ADDED] the function :code:`run_contingency` can raise a captured error if parameter :code:`raise_errors` is passed
+- [FIXED] bugfix for tap dependent impedance characteristics so that not all characteristics columns are necessary
 
 [2.13.1] - 2023-05-12
 -------------------------------

pandapower/build_branch.py

@@ -498,6 +498,7 @@ def _get_vk_values(trafo_df, characteristic, trafotype="2W"):
         # must cast to float64 unfortunately, because numpy.vstack casts arrays to object because it doesn't know pandas.NA, np.isnan fails
         all_characteristic_idx = np.vstack([get_trafo_values(
             trafo_df, f"{c}_characteristic").astype(np.float64) for c in char_columns]).T
+        index_column = {c: i for i, c in enumerate(char_columns)}
         # now we check if any trafos that have tap_dependent_impedance have all of the characteristics missing
         all_missing = np.isnan(all_characteristic_idx).all(axis=1) & tap_dependent_impedance
         if np.any(all_missing):
@@ -512,7 +513,7 @@ def _get_vk_values(trafo_df, characteristic, trafotype="2W"):
         if use_tap_dependent_impedance and vk_var in char_columns:
             vals += (_calc_tap_dependent_value(
                 trafo_df, tap_pos, vk_value, vk_var, tap_dependent_impedance,
-                characteristic, all_characteristic_idx[:, c]),)
+                characteristic, all_characteristic_idx[:, index_column[vk_var]]),)
         else:
             vals += (vk_value,)
 

pandapower/test/loadflow/test_results.py

@@ -370,30 +370,13 @@ def test_undefined_tap_dependent_impedance_characteristics_trafo3w():
     add_trafo_connection(net, 1, "3W")
     add_trafo_connection(net, 1, "3W")
 
-    pp.control.create_trafo_characteristics(net, 'trafo3w', [0, 1], 'vk_hv_percent', [[-2, -1, 0, 1, 2], [-2, -1, 0, 1, 2]], [[0.7, 0.9, 1, 1.1, 1.3], [0.7, 0.9, 1, 1.1, 1.3]])
     pp.control.create_trafo_characteristics(net, 'trafo3w', [0, 1], 'vk_mv_percent', [[-2, -1, 0, 1, 2], [-2, -1, 0, 1, 2]], [[0.7, 0.9, 1, 1.1, 1.3], [0.7, 0.9, 1, 1.1, 1.3]])
-    pp.control.create_trafo_characteristics(net, 'trafo3w', [0, 1], 'vk_lv_percent', [[-2, -1, 0, 1, 2], [-2, -1, 0, 1, 2]], [[0.7, 0.9, 1, 1.1, 1.3], [0.7, 0.9, 1, 1.1, 1.3]])
-    pp.control.create_trafo_characteristics(net, 'trafo3w', [0, 1], 'vkr_hv_percent', [[-2, -1, 0, 1, 2], [-2, -1, 0, 1, 2]], [[0.3, 0.45, 0.5, 0.55, 0.7], [0.3, 0.45, 0.5, 0.55, 0.7]])
     pp.control.create_trafo_characteristics(net, 'trafo3w', [0, 1], 'vkr_mv_percent', [[-2, -1, 0, 1, 2], [-2, -1, 0, 1, 2]], [[0.3, 0.45, 0.5, 0.55, 0.7], [0.3, 0.45, 0.5, 0.55, 0.7]])
-    pp.control.create_trafo_characteristics(net, 'trafo3w', [0, 1], 'vkr_lv_percent', [[-2, -1, 0, 1, 2], [-2, -1, 0, 1, 2]], [[0.3, 0.45, 0.5, 0.55, 0.7], [0.3, 0.45, 0.5, 0.55, 0.7]])
 
-
-    # does not raise error
-    pp.runpp(net)
-
-    # this will raise error
-    net.trafo3w.at[0, "vk_hv_percent_characteristic"] = None
     pp.runpp(net)
     net.trafo3w.at[0, "vk_mv_percent_characteristic"] = None
     pp.runpp(net)
-    net.trafo3w.at[0, "vk_lv_percent_characteristic"] = None
-    pp.runpp(net)
-
-    net.trafo3w.at[0, "vkr_hv_percent_characteristic"] = None
-    pp.runpp(net)
     net.trafo3w.at[0, "vkr_mv_percent_characteristic"] = None
-    pp.runpp(net)
-    net.trafo3w.at[0, "vkr_lv_percent_characteristic"] = None
     with pytest.raises(UserWarning):
         pp.runpp(net)