Fix slack distribution outerloop incorrect stable status (#1157)

Signed-off-by: Damien Jeandemange <[email protected]>
powsybl · Dec 18, 2024 · c7f69ad · c7f69ad
1 parent 78cf08a
commit c7f69ad
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Showing 3 changed files with 24 additions and 1 deletion.
diff --git a/src/main/java/com/powsybl/openloadflow/network/util/ActivePowerDistribution.java b/src/main/java/com/powsybl/openloadflow/network/util/ActivePowerDistribution.java
@@ -86,8 +86,10 @@ public Result run(LfGenerator referenceGenerator, Collection<LfBus> buses, doubl
             iteration++;
         }
 
+        // Identify if injections moved significantly, used e.g. to establish stable/unstable outer loop status.
+        // The 0.9 magic factor is to handle potential rounding issues.
         final boolean movedBuses = initialP.entrySet().stream()
-                .anyMatch(e -> Math.abs(e.getKey().getTargetP() - e.getValue()) > P_RESIDUE_EPS);
+                .mapToDouble(e -> Math.abs(e.getKey().getTargetP() - e.getValue())).sum() > P_RESIDUE_EPS * 0.9;
 
         return new Result(iteration, remainingMismatch, movedBuses);
     }

diff --git a/src/test/java/com/powsybl/openloadflow/ac/DistributedSlackOnGenerationTest.java b/src/test/java/com/powsybl/openloadflow/ac/DistributedSlackOnGenerationTest.java
@@ -642,4 +642,14 @@ void testSlackMismatchChangingSignReferenceGenerator() {
         assertActivePowerEquals(-90.000, g3.getTerminal());
         assertActivePowerEquals(-90.000, g4.getTerminal());
     }
+
+    @Test
+    void testEpsilonDistribution() {
+        parametersExt.setSlackBusPMaxMismatch(0.1);
+        network = DistributedSlackNetworkFactory.createWithEpsilonDistribution();
+        LoadFlowResult result = loadFlowRunner.run(network, parameters);
+        assertTrue(result.isFullyConverged());
+        assertEquals(0.0, result.getComponentResults().get(0).getSlackBusResults().get(0).getActivePowerMismatch(), LoadFlowAssert.DELTA_POWER);
+        assertEquals(0.15, result.getComponentResults().get(0).getDistributedActivePower(), LoadFlowAssert.DELTA_POWER);
+    }
 }
diff --git a/src/test/java/com/powsybl/openloadflow/network/DistributedSlackNetworkFactory.java b/src/test/java/com/powsybl/openloadflow/network/DistributedSlackNetworkFactory.java
@@ -222,4 +222,15 @@ public static Network createWithBattery() {
                 .add();
         return network;
     }
+
+    public static Network createWithEpsilonDistribution() {
+        // 0.15 MW slack mismatch to be distributed over 1000 generators
+        Network network = Network.create("distributed-generation-slack-bus", "code");
+        Bus b = createBus(network, "bus");
+        createLoad(b, "load", 1000.15);
+        for (int i = 0; i < 1000; i++) {
+            createGenerator(b, "g" + i, 1.0);
+        }
+        return network;
+    }
 }