Fix already converged case in fast restart mode (#802)

Signed-off-by: Geoffroy Jamgotchian <geoffroy.jamgotchian@rte-france.com>
(cherry picked from commit fbc684f)

src/main/java/com/powsybl/openloadflow/AcLoadFlowFromCache.java

@@ -14,6 +14,8 @@
 import com.powsybl.openloadflow.ac.AcLoadFlowParameters;
 import com.powsybl.openloadflow.ac.AcLoadFlowResult;
 import com.powsybl.openloadflow.ac.AcloadFlowEngine;
+import com.powsybl.openloadflow.ac.nr.NewtonRaphsonStatus;
+import com.powsybl.openloadflow.lf.outerloop.OuterLoopStatus;
 import com.powsybl.openloadflow.network.impl.LfNetworkList;
 import com.powsybl.openloadflow.network.impl.Networks;
 import org.slf4j.Logger;
@@ -93,13 +95,16 @@ private List<AcLoadFlowContext> initContexts(NetworkCache.Entry entry) {
     }
 
     private static AcLoadFlowResult run(AcLoadFlowContext context) {
-        if (context.getNetwork().isValid() && context.isNetworkUpdated()) {
+        if (!context.getNetwork().isValid()) {
+            return AcLoadFlowResult.createNoCalculationResult(context.getNetwork());
+        }
+        if (context.isNetworkUpdated()) {
             AcLoadFlowResult result = new AcloadFlowEngine(context)
                     .run();
             context.setNetworkUpdated(false);
             return result;
         }
-        return AcLoadFlowResult.createNoCalculationResult(context.getNetwork());
+        return new AcLoadFlowResult(context.getNetwork(), 0, 0, NewtonRaphsonStatus.CONVERGED, OuterLoopStatus.STABLE, 0d, 0d);
     }
 
     public List<AcLoadFlowResult> run() {

src/main/java/com/powsybl/openloadflow/NetworkCache.java

@@ -15,6 +15,7 @@
 import com.powsybl.openloadflow.network.LfShunt;
 import com.powsybl.openloadflow.network.GeneratorVoltageControl;
 import com.powsybl.openloadflow.network.*;
+import com.powsybl.openloadflow.network.impl.AbstractLfGenerator;
 import com.powsybl.openloadflow.network.util.PreviousValueVoltageInitializer;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -134,8 +135,18 @@ private boolean onGeneratorUpdate(Generator generator, String attribute, Object
                 if (attribute.equals("targetV")) {
                     double valueShift = (double) newValue - (double) oldValue;
                     GeneratorVoltageControl voltageControl = lfBus.getGeneratorVoltageControl().orElseThrow();
-                    double newTargetV = voltageControl.getTargetValue() + valueShift / lfBus.getNominalV();
-                    voltageControl.setTargetValue(newTargetV);
+                    double nominalV = voltageControl.getControlledBus().getNominalV();
+                    double newTargetV = voltageControl.getTargetValue() + valueShift / nominalV;
+                    LfNetworkParameters networkParameters = context.getParameters().getNetworkParameters();
+                    if (AbstractLfGenerator.checkTargetV(generator.getId(), newTargetV, nominalV, networkParameters, null)) {
+                        voltageControl.setTargetValue(newTargetV);
+                    } else {
+                        context.getNetwork().getGeneratorById(generator.getId()).setGeneratorControlType(LfGenerator.GeneratorControlType.OFF);
+                        if (lfBus.getGenerators().stream().noneMatch(gen -> gen.getGeneratorControlType() == LfGenerator.GeneratorControlType.VOLTAGE)) {
+                            lfBus.setGeneratorVoltageControlEnabled(false);
+                        }
+                    }
+                    context.getNetwork().validate(LoadFlowModel.AC, null);
                     return true;
                 }
                 return false;

src/main/java/com/powsybl/openloadflow/OpenLoadFlowProvider.java

@@ -130,7 +130,7 @@ private LoadFlowResult runAc(Network network, LoadFlowParameters parameters, Ope
         List<LoadFlowResult.ComponentResult> componentResults = new ArrayList<>(results.size());
         for (AcLoadFlowResult result : results) {
             // update network state
-            if (result.getNewtonRaphsonStatus() == NewtonRaphsonStatus.CONVERGED || parametersExt.isAlwaysUpdateNetwork()) {
+            if ((result.getNewtonRaphsonStatus() == NewtonRaphsonStatus.CONVERGED && result.getNewtonRaphsonIterations() > 0) || parametersExt.isAlwaysUpdateNetwork()) {
                 var updateParameters = new LfNetworkStateUpdateParameters(parameters.isUseReactiveLimits(),
                                                                           parameters.isWriteSlackBus(),
                                                                           parameters.isPhaseShifterRegulationOn(),

src/main/java/com/powsybl/openloadflow/network/LfNetwork.java

@@ -490,16 +490,18 @@ public void fix(boolean minImpedance, double lowImpedanceThreshold) {
 
     private void validateBuses(LoadFlowModel loadFlowModel, Reporter reporter) {
         if (loadFlowModel == LoadFlowModel.AC) {
-            boolean hasAtLeastOneBusVoltageControlled = false;
+            boolean hasAtLeastOneBusGeneratorVoltageControlEnabled = false;
             for (LfBus bus : busesByIndex) {
-                if (bus.isGeneratorVoltageControlled()) {
-                    hasAtLeastOneBusVoltageControlled = true;
+                if (bus.isGeneratorVoltageControlEnabled()) {
+                    hasAtLeastOneBusGeneratorVoltageControlEnabled = true;
                     break;
                 }
             }
-            if (!hasAtLeastOneBusVoltageControlled) {
-                LOGGER.error("Network {} must have at least one bus voltage controlled", this);
-                Reports.reportNetworkMustHaveAtLeastOneBusVoltageControlled(reporter);
+            if (!hasAtLeastOneBusGeneratorVoltageControlEnabled) {
+                LOGGER.error("Network {} must have at least one bus with generator voltage control enabled", this);
+                if (reporter != null) {
+                    Reports.reportNetworkMustHaveAtLeastOneBusGeneratorVoltageControlEnabled(reporter);
+                }
                 valid = false;
             }
         }

src/main/java/com/powsybl/openloadflow/network/impl/AbstractLfGenerator.java

@@ -212,7 +212,7 @@ protected void setVoltageControl(double targetV, Terminal terminal, Terminal reg
             LOGGER.warn("Regulating terminal of LfGenerator {} is not in the same synchronous component: voltage control discarded", getId());
             return;
         }
-        if (!checkTargetV(targetV / regulatingTerminal.getVoltageLevel().getNominalV(), regulatingTerminal.getVoltageLevel().getNominalV(), parameters, report)) {
+        if (!checkTargetV(getId(), targetV / regulatingTerminal.getVoltageLevel().getNominalV(), regulatingTerminal.getVoltageLevel().getNominalV(), parameters, report)) {
             return;
         }
         this.controlledBusId = controlledBus.getId();
@@ -262,13 +262,15 @@ protected boolean checkVoltageControlConsistency(LfNetworkParameters parameters,
         return consistency;
     }
 
-    protected boolean checkTargetV(double targetV, double nominalV, LfNetworkParameters parameters, LfNetworkLoadingReport report) {
+    public static boolean checkTargetV(String generatorId, double targetV, double nominalV, LfNetworkParameters parameters, LfNetworkLoadingReport report) {
         // check that targetV has a plausible value (wrong nominal voltage issue)
         if (nominalV > parameters.getMinNominalVoltageTargetVoltageCheck() &&
                 (targetV < parameters.getMinPlausibleTargetVoltage() || targetV > parameters.getMaxPlausibleTargetVoltage())) {
             LOGGER.trace("Generator '{}' has an inconsistent target voltage: {} pu: generator voltage control discarded",
-                getId(), targetV);
-            report.generatorsWithInconsistentTargetVoltage++;
+                generatorId, targetV);
+            if (report != null) {
+                report.generatorsWithInconsistentTargetVoltage++;
+            }
             return false;
         }
         return true;

src/main/java/com/powsybl/openloadflow/network/impl/LfDanglingLineGenerator.java

@@ -31,7 +31,7 @@ private LfDanglingLineGenerator(DanglingLine danglingLine, LfNetwork network, St
         // local control only
         if (danglingLine.getGeneration().isVoltageRegulationOn() && checkVoltageControlConsistency(parameters, report)) {
             // The controlled bus cannot be reached from the DanglingLine parameters (there is no terminal in DanglingLine.Generation)
-            if (checkTargetV(danglingLine.getGeneration().getTargetV() / danglingLine.getTerminal().getVoltageLevel().getNominalV(),
+            if (checkTargetV(getId(), danglingLine.getGeneration().getTargetV() / danglingLine.getTerminal().getVoltageLevel().getNominalV(),
                     danglingLine.getTerminal().getVoltageLevel().getNominalV(), parameters, report)) {
                 this.controlledBusId = Objects.requireNonNull(controlledLfBusId);
                 this.targetV = danglingLine.getGeneration().getTargetV() / danglingLine.getTerminal().getVoltageLevel().getNominalV();

src/main/java/com/powsybl/openloadflow/util/Reports.java

@@ -47,10 +47,10 @@ public static void reportNetworkBalance(Reporter reporter, double activeGenerati
                 .build());
     }
 
-    public static void reportNetworkMustHaveAtLeastOneBusVoltageControlled(Reporter reporter) {
+    public static void reportNetworkMustHaveAtLeastOneBusGeneratorVoltageControlEnabled(Reporter reporter) {
         reporter.report(Report.builder()
-                .withKey("networkMustHaveAtLeastOneBusVoltageControlled")
-                .withDefaultMessage("Network must have at least one bus voltage controlled")
+                .withKey("networkMustHaveAtLeastOneBusGeneratorVoltageControlEnabled")
+                .withDefaultMessage("Network must have at least one bus with generator voltage control enabled")
                 .build());
     }
 

src/test/java/com/powsybl/openloadflow/ac/AcLoadFlowEurostagTutorialExample1Test.java

@@ -288,7 +288,7 @@ void noGeneratorTest() {
         ReporterModel postLoadingReporter = createNetworkReporter.getSubReporters().get(0);
         assertEquals("postLoadingProcessing", postLoadingReporter.getTaskKey());
         assertEquals(1, postLoadingReporter.getReports().size());
-        assertEquals("Network must have at least one bus voltage controlled",
+        assertEquals("Network must have at least one bus with generator voltage control enabled",
                 postLoadingReporter.getReports().iterator().next().getDefaultMessage());
     }
 

src/test/java/com/powsybl/openloadflow/ac/AcLoadFlowWithCachingTest.java

@@ -74,8 +74,7 @@ void testTargetV() {
 
         result = loadFlowRunner.run(network, parameters);
         assertEquals(1, NetworkCache.INSTANCE.getEntryCount());
-        // FIXME NO_CALCULATION should be added to API
-        assertEquals(LoadFlowResult.ComponentResult.Status.FAILED, result.getComponentResults().get(0).getStatus());
+        assertEquals(LoadFlowResult.ComponentResult.Status.CONVERGED, result.getComponentResults().get(0).getStatus());
         assertEquals(0, result.getComponentResults().get(0).getIterationCount());
     }
 
@@ -333,4 +332,33 @@ void testSwitchClose() {
         assertActivePowerEquals(301.884, l1.getTerminal1());
         assertActivePowerEquals(301.884, l2.getTerminal1());
     }
+
+    @Test
+    void testInvalidNetwork() {
+        var network = EurostagFactory.fix(EurostagTutorialExample1Factory.create());
+        var result = loadFlowRunner.run(network, parameters);
+
+        assertNotNull(NetworkCache.INSTANCE.findEntry(network).orElseThrow().getContexts());
+
+        var gen = network.getGenerator("GEN");
+        gen.setTargetV(1000);
+        result = loadFlowRunner.run(network, parameters);
+        assertEquals(LoadFlowResult.ComponentResult.Status.FAILED, result.getComponentResults().get(0).getStatus());
+    }
+
+    @Test
+    @Disabled("To support later")
+    void testInitiallyInvalidNetwork() {
+        var network = EurostagFactory.fix(EurostagTutorialExample1Factory.create());
+        var gen = network.getGenerator("GEN");
+        gen.setTargetV(1000);
+        var result = loadFlowRunner.run(network, parameters);
+        assertEquals(LoadFlowResult.ComponentResult.Status.FAILED, result.getComponentResults().get(0).getStatus());
+
+        assertNotNull(NetworkCache.INSTANCE.findEntry(network).orElseThrow().getContexts());
+
+        gen.setTargetV(24);
+        result = loadFlowRunner.run(network, parameters);
+        assertEquals(LoadFlowResult.ComponentResult.Status.CONVERGED, result.getComponentResults().get(0).getStatus());
+    }
 }