cgmes: fix voltage regulating control defined at busbar section (#3666)

* fix voltage regulating control defined at busbar section
* Improve the method. A more complex unit test
* Apply the reviewer's comments

Signed-off-by: marquesja1 <marquesja@aia.es>

Author: marqueslanauja

cgmes/cgmes-conversion/src/main/java/com/powsybl/cgmes/conversion/RegulatingTerminalMapper.java

@@ -42,9 +42,11 @@ public static Optional<Terminal> mapForVoltageControl(String cgmesTerminalId, Co
                         .or(() -> new EquivalentTerminalFinderVoltageControl(cgmesTerminalId, context).find())
                         // As a last resource, rely on the "find" method of terminal mapping:
                         // Bus/branch models may define remote voltage controls that point to busbar sections
-                        // Busbar sections are not mapped to IIDM
+                        // Since busbar sections are not mapped to IIDM, we look for an equivalent IIDM terminal
+                        // that is connected to the busbar section via switches
                         .or(() -> Optional.ofNullable(context.terminalMapping()
-                                .findFromTopologicalNode(context.terminalMapping().getTopologicalNode(cgmesTerminalId))));
+                                .findFromTopologicalNode(context.terminalMapping().getTopologicalNode(cgmesTerminalId)))
+                                .or(() -> findEquivalentTerminalForVoltageRegulatingTerminalDefinedAtBusbarSection(cgmesTerminalId, context)));
     }
 
     public static Optional<TerminalAndSign> mapForFlowControl(String cgmesTerminalId, Context context) {
@@ -337,7 +339,7 @@ private Optional<Terminal> findNodeBreaker() {
 
         private Optional<Terminal> findBusBranch() {
             Bus end1 = vl.getBusBreakerView().getBus1(sw.getId());
-            List<Terminal> terminals = findTerminalsBusBranch(end1);
+            List<Terminal> terminals = findTerminalsBusBranch(vl, end1);
             return best(terminals);
         }
 
@@ -346,7 +348,7 @@ protected List<Terminal> findTerminalsNodeBreaker(int node) {
             return allTerminals(vl, nodes, t -> t.getNodeBreakerView().getNode());
         }
 
-        private List<Terminal> findTerminalsBusBranch(Bus end) {
+        private static List<Terminal> findTerminalsBusBranch(VoltageLevel vl, Bus end) {
             Set<Bus> buses = allBusesReachableBySwitches(vl, end);
             return allTerminals(vl, buses, RegulatingTerminalMapper::getTerminalBus);
         }
@@ -399,6 +401,17 @@ private Optional<Terminal> findBusBranch() {
         }
     }
 
+    static Optional<Terminal> findEquivalentTerminalForVoltageRegulatingTerminalDefinedAtBusbarSection(String cgmesTerminalId, Context context) {
+        CgmesTerminal busbarSectionCgmesTerminal = context.cgmes().terminal(cgmesTerminalId);
+        if (busbarSectionCgmesTerminal == null) {
+            return Optional.empty();
+        }
+        Bus busInBusBreakerView = context.network().getBusBreakerView().getBus(busbarSectionCgmesTerminal.topologicalNode());
+        return busInBusBreakerView != null
+                ? EquivalentTerminalFinderVoltageControl.best(EquivalentTerminalFinderVoltageControl.findTerminalsBusBranch(busInBusBreakerView.getVoltageLevel(), busInBusBreakerView))
+                : Optional.empty();
+    }
+
     private static Bus getTerminalBus(Terminal terminal) {
         return terminal.getBusBreakerView().getBus() != null ? terminal.getBusBreakerView().getBus()
             : terminal.getBusBreakerView().getConnectableBus();

cgmes/cgmes-conversion/src/test/java/com/powsybl/cgmes/conversion/test/RegulatingTerminalConversionTest.java

@@ -10,13 +10,16 @@
 
 import com.powsybl.cgmes.conformity.Cgmes3ModifiedCatalog;
 import com.powsybl.cgmes.conformity.CgmesConformity1ModifiedCatalog;
+import com.powsybl.cgmes.conversion.CgmesImport;
 import com.powsybl.cgmes.conversion.Conversion;
 import com.powsybl.cgmes.model.GridModelReference;
 import com.powsybl.iidm.network.*;
 import org.junit.jupiter.api.Test;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertNotNull;
+import java.util.Properties;
+
+import static com.powsybl.cgmes.conversion.test.ConversionUtil.readCgmesResources;
+import static org.junit.jupiter.api.Assertions.*;
 
 /**
  * @author Luma Zamarreño {@literal <zamarrenolm at aia.es>}
@@ -86,6 +89,35 @@ void microGridBaseBECaseRegulatingTerminalsDefinedOnSwitches() {
         assertEquals(21.987, regulationValue, 0.0);
     }
 
+    @Test
+    void voltageRegulatingTerminalAtBusbarSectionNodeBreakerTest() {
+        Network network = readCgmesResources("/issues/voltage-regulating-terminal-at-busbar-section",
+                "issue_3560_CGMES_EQ.xml",
+                "issue_3560_CGMES_SSH.xml");
+
+        Generator generator = network.getGenerator("GEN");
+        assertNotNull(generator);
+        assertEquals("VL2_400_BBS1", generator.getRegulatingTerminal().getConnectable().getId());
+        assertSame(IdentifiableType.BUSBAR_SECTION, generator.getRegulatingTerminal().getConnectable().getType());
+    }
+
+    @Test
+    void voltageRegulatingTerminalAtBusbarSectionBusBreakerTest() {
+        Properties importParams = new Properties();
+        importParams.put(CgmesImport.IMPORT_NODE_BREAKER_AS_BUS_BREAKER, "true");
+
+        Network network = readCgmesResources(importParams,
+                "/issues/voltage-regulating-terminal-at-busbar-section",
+                "issue_3560_CGMES_EQ.xml",
+                "issue_3560_CGMES_SSH.xml",
+                "issue_3560_CGMES_TP.xml");
+
+        Generator generator = network.getGenerator("GEN");
+        assertNotNull(generator);
+        assertEquals("LOAD", generator.getRegulatingTerminal().getConnectable().getId());
+        assertSame(IdentifiableType.LOAD, generator.getRegulatingTerminal().getConnectable().getType());
+    }
+
     private Network networkModel(GridModelReference testGridModel, Conversion.Config config) {
         config.setConvertSvInjections(true);
         return ConversionUtil.networkModel(testGridModel, config);