BugFix: unify fast_any_tap behavior when handling small u_band (smaller than tap_size)

power_grid_model_c/power_grid_model/include/power_grid_model/optimizer/tap_position_optimizer.hpp

@@ -21,6 +21,7 @@
 #include <boost/graph/compressed_sparse_row_graph.hpp>
 
 #include <algorithm>
+#include <compare>
 #include <functional>
 #include <numeric>
 #include <optional>
@@ -62,10 +63,10 @@ struct TrafoGraphEdge {
     } // thanks boost
 
     auto constexpr operator<=>(TrafoGraphEdge const& other) const {
-        if (auto cmp = weight <=> other.weight; cmp != 0) { // NOLINT(modernize-use-nullptr)
+        if (auto cmp = weight <=> other.weight; std::is_neq(cmp)) {
             return cmp;
         }
-        if (auto cmp = regulated_idx.group <=> other.regulated_idx.group; cmp != 0) { // NOLINT(modernize-use-nullptr)
+        if (auto cmp = regulated_idx.group <=> other.regulated_idx.group; std::is_neq(cmp)) {
             return cmp;
         }
         return regulated_idx.pos <=> other.regulated_idx.pos;
@@ -804,6 +805,10 @@ class TapPositionOptimizerImpl<std::tuple<TransformerTypes...>, StateCalculator,
             return tap_pos;
         }
 
+        void rewind(IntS tap_pos, IntS tap_min, IntS tap_max) {
+            reset(tap_pos, tap_min, tap_max, control_at_tap_side_);
+        }
+
       private:
         void reset(IntS tap_pos, IntS tap_min, IntS tap_max, bool control_at_tap_side) {
             last_down_ = false;
@@ -1085,10 +1090,10 @@ class TapPositionOptimizerImpl<std::tuple<TransformerTypes...>, StateCalculator,
 
             auto const cmp = node_state <=> param;
             auto new_tap_pos = [&transformer, &cmp, &control_at_tap_side] {
-                if (cmp > 0) { // NOLINT(modernize-use-nullptr)
+                if (std::is_gt(cmp)) {
                     return one_step_control_voltage_down(transformer, control_at_tap_side);
                 }
-                if (cmp < 0) { // NOLINT(modernize-use-nullptr)
+                if (std::is_lt(cmp)) {
                     return one_step_control_voltage_up(transformer, control_at_tap_side);
                 }
                 return transformer.tap_pos();
@@ -1126,8 +1131,8 @@ class TapPositionOptimizerImpl<std::tuple<TransformerTypes...>, StateCalculator,
             auto const cmp = node_state <=> param;
             if (auto new_tap_pos =
                     [&cmp, strategy_max, &current_bs] {
-                        if (cmp != 0) {                                        // NOLINT(modernize-use-nullptr)
-                            current_bs.propose_new_pos(strategy_max, cmp > 0); // NOLINT(modernize-use-nullptr)
+                        if (std::is_neq(cmp)) {
+                            current_bs.propose_new_pos(strategy_max, std::is_gt(cmp));
                         }
                         return current_bs.get_current_tap();
                     }();
@@ -1138,7 +1143,7 @@ class TapPositionOptimizerImpl<std::tuple<TransformerTypes...>, StateCalculator,
                 return;
             }
 
-            if (strategy_ == OptimizerStrategy::fast_any) {
+            if (strategy_ == OptimizerStrategy::fast_any && std::is_eq(cmp)) {
                 tap_changed = false;
                 return;
             }
@@ -1147,6 +1152,16 @@ class TapPositionOptimizerImpl<std::tuple<TransformerTypes...>, StateCalculator,
             current_bs.recalibrate(strategy_max);
 
             IntS const tap_pos = current_bs.repropose_tap(strategy_max, previous_down, tap_changed);
+            // The new same tap pos is only valid in a cmp == equivalent situation
+            // in other words, a same tap pos in a non equivalent situation means
+            // the binary search cannot find a valid tap position
+            // _tap_changed_ is an aggregated flag with _inevitable_run_, so we can not use it here
+            if (tap_pos == transformer.tap_pos() && cmp != 0 && !current_bs.get_end_of_bs()) {
+                current_bs.rewind(tap_pos, transformer.tap_min(), transformer.tap_max());
+                throw MaxIterationReached{std::format(
+                    "TapPositionOptimizer::binary_search: no valid tap position found between tap {} and tap {}",
+                    transformer.tap_min(), transformer.tap_max())};
+            }
             add_tap_pos_update(tap_pos, transformer, update_data);
         };
         regulator.transformer.apply(adjust_transformer_);

tests/data/power_flow/automatic-tap-regulator/achievable-voltage-above-band-fast-any/params.json

@@ -7,7 +7,7 @@
     "u": 100.0
   },
    "xfail": {
-    "raises": "AssertionError",
+    "raises": "MaxIterationReached",
     "reason": "Bug in fast any tap changing strategy in this edge case: https://github.com/PowerGridModel/power-grid-model/issues/1215"
   }
 }

tests/data/power_flow/automatic-tap-regulator/auto-tap-changer-meshed-fast-any-max-iter/input.json

@@ -0,0 +1,59 @@
+{
+  "version": "1.0",
+  "type": "input",
+  "is_batch": false,
+  "attributes": {},
+  "data": {
+    "node": [
+      {"id": 0, "u_rated": 10000},
+      {"id": 1, "u_rated": 10000},
+      {"id": 2, "u_rated": 10000},
+      {"id": 3, "u_rated": 10000},
+      {"id": 4, "u_rated": 10000},
+      {"id": 5, "u_rated": 10000},
+      {"id": 6, "u_rated": 10000},
+      {"id": 7, "u_rated": 400},
+      {"id": 8, "u_rated": 400},
+      {"id": 9, "u_rated": 400},
+      {"id": 10, "u_rated": 400}
+    ],
+    "line": [
+      {"id": 11, "from_node": 0, "to_node": 1, "from_status": 1, "to_status": 1, "r1": 0.005, "x1": 0.5, "c1": 0, "tan1": 0},
+      {"id": 12, "from_node": 0, "to_node": 2, "from_status": 1, "to_status": 1, "r1": 0.1, "x1": 0.6, "c1": 0, "tan1": 0},
+      {"id": 13, "from_node": 3, "to_node": 5, "from_status": 1, "to_status": 1, "r1": 0.005, "x1": 0.5, "c1": 0, "tan1": 0},
+      {"id": 14, "from_node": 4, "to_node": 6, "from_status": 1, "to_status": 1, "r1": 0.003, "x1": 0.3, "c1": 0, "tan1": 0},
+      {"id": 15, "from_node": 7, "to_node": 9, "from_status": 1, "to_status": 1, "r1": 0.005, "x1": 0.5, "c1": 0, "tan1": 0},
+      {"id": 16, "from_node": 8, "to_node": 9, "from_status": 1, "to_status": 1, "r1": 0.005, "x1": 0.6, "c1": 0, "tan1": 0}
+    ],
+    "transformer": [
+      {"id": 17, "from_node": 1, "to_node": 3, "from_status": 1, "to_status": 1, "u1": 10000, "u2": 10000, "sn": 300000, "uk": 0.0005, "pk": 1000, "i0": 0, "p0": 0, "winding_from": 2, "winding_to": 1, "clock": 5, "tap_side": 0, "tap_pos": 0, "tap_min": -10, "tap_max": 10, "tap_size": 100},
+      {"id": 18, "from_node": 2, "to_node": 4, "from_status": 1, "to_status": 1, "u1": 10000, "u2": 10000, "sn": 300000, "uk": 0.0005, "pk": 1000, "i0": 0, "p0": 0, "winding_from": 2, "winding_to": 1, "clock": 5, "tap_side": 0, "tap_pos": 0, "tap_min": -10, "tap_max": 10, "tap_size": 100},
+      {"id": 19, "from_node": 5, "to_node": 7, "from_status": 1, "to_status": 1, "u1": 10000, "u2": 400, "sn": 300000, "uk": 0.0005, "pk": 1000, "i0": 0, "p0": 0, "winding_from": 2, "winding_to": 1, "clock": 5, "tap_side": 0, "tap_pos": 0, "tap_min": -10, "tap_max": 10, "tap_size": 20},
+      {"id": 20, "from_node": 6, "to_node": 8, "from_status": 1, "to_status": 1, "u1": 10000, "u2": 400, "sn": 300000, "uk": 0.0005, "pk": 1000, "i0": 0, "p0": 0, "winding_from": 2, "winding_to": 1, "clock": 5, "tap_side": 0, "tap_pos": 0, "tap_min": -10, "tap_max": 10, "tap_size": 20},
+      {"id": 21, "from_node": 9, "to_node": 10, "from_status": 1, "to_status": 1, "u1": 400, "u2": 400, "sn": 300000, "uk": 0.0005, "pk": 1000, "i0": 0, "p0": 0, "winding_from": 2, "winding_to": 1, "clock": 5, "tap_side": 0, "tap_pos": 0, "tap_min": -10, "tap_max": 10, "tap_size": 20}
+    ],
+    "source": [
+      {"id": 22, "node": 0, "status": 1, "u_ref": 1}
+    ],
+    "sym_load": [
+      {"id": 23, "node": 0, "status": 1, "type": 0, "p_specified": 100000, "q_specified": 10000},
+      {"id": 24, "node": 1, "status": 1, "type": 0, "p_specified": 100000, "q_specified": 10000},
+      {"id": 25, "node": 2, "status": 1, "type": 0, "p_specified": 100000, "q_specified": 10000},
+      {"id": 26, "node": 3, "status": 1, "type": 0, "p_specified": 100000, "q_specified": 10000},
+      {"id": 27, "node": 4, "status": 1, "type": 0, "p_specified": 100000, "q_specified": 10000},
+      {"id": 28, "node": 5, "status": 1, "type": 0, "p_specified": 100000, "q_specified": 10000},
+      {"id": 29, "node": 6, "status": 1, "type": 0, "p_specified": 100000, "q_specified": 10000},
+      {"id": 30, "node": 7, "status": 1, "type": 0, "p_specified": 100000, "q_specified": 10000},
+      {"id": 31, "node": 8, "status": 1, "type": 0, "p_specified": 100000, "q_specified": 10000},
+      {"id": 32, "node": 9, "status": 1, "type": 0, "p_specified": 100000, "q_specified": 10000},
+      {"id": 33, "node": 10, "status": 1, "type": 0, "p_specified": 100000, "q_specified": 10000}
+    ],
+    "transformer_tap_regulator": [
+      {"id": 34, "regulated_object": 17, "status": 1, "control_side": 1, "u_set": 10000, "u_band": 300},
+      {"id": 35, "regulated_object": 18, "status": 1, "control_side": 1, "u_set": 10000, "u_band": 300},
+      {"id": 36, "regulated_object": 19, "status": 1, "control_side": 1, "u_set": 400, "u_band": 5},
+      {"id": 37, "regulated_object": 20, "status": 1, "control_side": 1, "u_set": 400, "u_band": 5},
+      {"id": 38, "regulated_object": 21, "status": 1, "control_side": 1, "u_set": 400, "u_band": 5}
+    ]
+  }
+}

tests/data/power_flow/automatic-tap-regulator/auto-tap-changer-meshed-fast-any-max-iter/input.json.license

@@ -0,0 +1,3 @@
+SPDX-FileCopyrightText: 2023 Contributors to the Power Grid Model project <dynamic.grid.calculation@alliander.com>
+
+SPDX-License-Identifier: MPL-2.0

tests/data/power_flow/automatic-tap-regulator/auto-tap-changer-meshed-fast-any-max-iter/params.json

@@ -0,0 +1,10 @@
+{
+  "calculation_method": "newton_raphson",
+  "tap_changing_strategy": "fast_any_tap",
+  "rtol": 1e-05,
+  "atol": 1e-05,
+  "raises": {
+    "raises": "MaxIterationReached",
+    "reason": "TapPositionOptimizer::iterate"
+  }
+}

tests/data/power_flow/automatic-tap-regulator/auto-tap-changer-meshed-fast-any-max-iter/params.json.license

@@ -0,0 +1,3 @@
+SPDX-FileCopyrightText: 2023 Contributors to the Power Grid Model project <dynamic.grid.calculation@alliander.com>
+
+SPDX-License-Identifier: MPL-2.0

tests/data/power_flow/automatic-tap-regulator/auto-tap-changer-meshed-fast-any-max-iter/sym_output.json

@@ -0,0 +1,7 @@
+{
+  "version": "1.0",
+  "type": "sym_output",
+  "is_batch": false,
+  "attributes": {},
+  "data": {}
+}

tests/data/power_flow/automatic-tap-regulator/auto-tap-changer-meshed-fast-any-max-iter/sym_output.json.license

@@ -0,0 +1,3 @@
+SPDX-FileCopyrightText: 2023 Contributors to the Power Grid Model project <dynamic.grid.calculation@alliander.com>
+
+SPDX-License-Identifier: MPL-2.0

tests/data/power_flow/automatic-tap-regulator/auto-tap-changer-small-u-band-max-iter-any/input.json

@@ -0,0 +1,71 @@
+{
+  "version": "1.0",
+  "type": "input",
+  "is_batch": false,
+  "attributes": {},
+  "data": {
+    "node": [
+      {
+        "id": 1,
+        "u_rated": 10000
+      },
+      {
+        "id": 2,
+        "u_rated": 400
+      }
+    ],
+    "source": [
+      {
+        "id": 3,
+        "node": 1,
+        "status": 1,
+        "u_ref": 1
+      }
+    ],
+    "sym_load": [
+      {
+        "id": 4,
+        "node": 2,
+        "status": 1,
+        "type": 0,
+        "p_specified": 5000,
+        "q_specified": 1015
+      }
+    ],
+    "transformer": [
+      {
+        "id": 5,
+        "from_node": 1,
+        "to_node": 2,
+        "from_status": 1,
+        "to_status": 1,
+        "u1": 10000,
+        "u2": 400,
+        "sn": 100000,
+        "uk": 0.04,
+        "pk": 1000,
+        "i0": 0.01,
+        "p0": 100,
+        "winding_from": 2,
+        "winding_to": 2,
+        "clock": 0,
+        "tap_side": 0,
+        "tap_pos": 2,
+        "tap_min": 1,
+        "tap_max": 5,
+        "tap_nom": 3,
+        "tap_size": 250
+      }
+    ],
+    "transformer_tap_regulator": [
+      {
+        "id": 6,
+        "regulated_object": 5,
+        "status": 1,
+        "control_side": 1,
+        "u_set": 400,
+        "u_band": 0.00001
+      }
+    ]
+  }
+}

tests/data/power_flow/automatic-tap-regulator/auto-tap-changer-small-u-band-max-iter-any/input.json.license

@@ -0,0 +1,3 @@
+SPDX-FileCopyrightText: 2023 Contributors to the Power Grid Model project <dynamic.grid.calculation@alliander.com>
+
+SPDX-License-Identifier: MPL-2.0

tests/data/power_flow/automatic-tap-regulator/auto-tap-changer-small-u-band-max-iter-any/params.json

@@ -0,0 +1,10 @@
+{
+  "calculation_method": "newton_raphson",
+  "tap_changing_strategy": "any_valid_tap",
+  "rtol": 1e-05,
+  "atol": 1e-05,
+  "raises": {
+    "raises": "MaxIterationReached",
+    "reason": "TapPositionOptimizer::binary_search"
+  }
+}

tests/data/power_flow/automatic-tap-regulator/auto-tap-changer-small-u-band-max-iter-any/params.json.license

@@ -0,0 +1,3 @@
+SPDX-FileCopyrightText: 2023 Contributors to the Power Grid Model project <dynamic.grid.calculation@alliander.com>
+
+SPDX-License-Identifier: MPL-2.0

tests/data/power_flow/automatic-tap-regulator/auto-tap-changer-small-u-band-max-iter-any/sym_output.json

@@ -0,0 +1,15 @@
+{
+  "version": "1.0",
+  "type": "sym_output",
+  "is_batch": false,
+  "attributes": {},
+  "data": {
+    "node": [
+      {"id": 1, "u_pu": 1, "u": 9999.9},
+      {"id": 2, "u_pu": 1.02456, "u": 409.8260092982474}
+    ],
+    "transformer_tap_regulator": [
+      {"id": 6, "tap_pos": 2}
+    ]
+  }
+}

tests/data/power_flow/automatic-tap-regulator/auto-tap-changer-small-u-band-max-iter-any/sym_output.json.license

@@ -0,0 +1,3 @@
+SPDX-FileCopyrightText: 2023 Contributors to the Power Grid Model project <dynamic.grid.calculation@alliander.com>
+
+SPDX-License-Identifier: MPL-2.0

tests/data/power_flow/automatic-tap-regulator/auto-tap-changer-small-u-band-max-iter-fast-any/input.json

@@ -0,0 +1,71 @@
+{
+  "version": "1.0",
+  "type": "input",
+  "is_batch": false,
+  "attributes": {},
+  "data": {
+    "node": [
+      {
+        "id": 1,
+        "u_rated": 10000
+      },
+      {
+        "id": 2,
+        "u_rated": 400
+      }
+    ],
+    "source": [
+      {
+        "id": 3,
+        "node": 1,
+        "status": 1,
+        "u_ref": 1
+      }
+    ],
+    "sym_load": [
+      {
+        "id": 4,
+        "node": 2,
+        "status": 1,
+        "type": 0,
+        "p_specified": 5000,
+        "q_specified": 1015
+      }
+    ],
+    "transformer": [
+      {
+        "id": 5,
+        "from_node": 1,
+        "to_node": 2,
+        "from_status": 1,
+        "to_status": 1,
+        "u1": 10000,
+        "u2": 400,
+        "sn": 100000,
+        "uk": 0.04,
+        "pk": 1000,
+        "i0": 0.01,
+        "p0": 100,
+        "winding_from": 2,
+        "winding_to": 2,
+        "clock": 0,
+        "tap_side": 0,
+        "tap_pos": 2,
+        "tap_min": 1,
+        "tap_max": 5,
+        "tap_nom": 3,
+        "tap_size": 250
+      }
+    ],
+    "transformer_tap_regulator": [
+      {
+        "id": 6,
+        "regulated_object": 5,
+        "status": 1,
+        "control_side": 1,
+        "u_set": 400,
+        "u_band": 0.00001
+      }
+    ]
+  }
+}

tests/data/power_flow/automatic-tap-regulator/auto-tap-changer-small-u-band-max-iter-fast-any/input.json.license

@@ -0,0 +1,3 @@
+SPDX-FileCopyrightText: 2023 Contributors to the Power Grid Model project <dynamic.grid.calculation@alliander.com>
+
+SPDX-License-Identifier: MPL-2.0

tests/data/power_flow/automatic-tap-regulator/auto-tap-changer-small-u-band-max-iter-fast-any/params.json

@@ -0,0 +1,10 @@
+{
+  "calculation_method": "newton_raphson",
+  "tap_changing_strategy": "fast_any_tap",
+  "rtol": 1e-05,
+  "atol": 1e-05,
+  "raises": {
+    "raises": "MaxIterationReached",
+    "reason": "TapPositionOptimizer::binary_search"
+  }
+}